15717521000119106: Osteochondritis dissecans of bilateral knee regions (disorder)

SNOMED CT Concept\Clinical finding (finding)\...

\Finding of limb structure\Disorder of limb (disorder)\Disorder of lower limb\Disorder of left lower extremity (disorder)\Injury of left lower limb (disorder)\Injury of left knee (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Disorder of limb (disorder)\Disorder of lower limb\Disorder of right lower extremity (disorder)\Injury of right lower limb (disorder)\Injury of right knee (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Disorder of limb (disorder)\Disorder of lower limb\Disorder of free lower limb (disorder)\Injury of free lower limb\Injury of knee\Injury of right knee (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Disorder of limb (disorder)\Disorder of lower limb\Disorder of free lower limb (disorder)\Injury of free lower limb\Injury of knee\Injury of left knee (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Disorder of limb (disorder)\Disorder of lower limb\Disorder of free lower limb (disorder)\Injury of free lower limb\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Disorder of limb (disorder)\Disorder of lower limb\Disorder of free lower limb (disorder)\Injury of free lower limb\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Disorder of limb (disorder)\Disorder of lower limb\Disorder of free lower limb (disorder)\Disorder of knee (disorder)\Injury of knee\Injury of right knee (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Disorder of limb (disorder)\Disorder of lower limb\Disorder of free lower limb (disorder)\Disorder of knee (disorder)\Injury of knee\Injury of left knee (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Disorder of limb (disorder)\Disorder of lower limb\Disorder of free lower limb (disorder)\Disorder of knee (disorder)\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Disorder of limb (disorder)\Disorder of lower limb\Disorder of free lower limb (disorder)\Disorder of knee (disorder)\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Disorder of limb (disorder)\Disorder of lower limb\Injury of lower limb\Injury of left lower limb (disorder)\Injury of left knee (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Disorder of limb (disorder)\Disorder of lower limb\Injury of lower limb\Injury of right lower limb (disorder)\Injury of right knee (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Disorder of limb (disorder)\Disorder of lower limb\Injury of lower limb\Injury of free lower limb\Injury of knee\Injury of right knee (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Disorder of limb (disorder)\Disorder of lower limb\Injury of lower limb\Injury of free lower limb\Injury of knee\Injury of left knee (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Disorder of limb (disorder)\Disorder of lower limb\Injury of lower limb\Injury of free lower limb\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Disorder of limb (disorder)\Disorder of lower limb\Injury of lower limb\Injury of free lower limb\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Finding of lower limb\Finding of bone of lower limb (finding)\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Finding of lower limb\Finding of bone of lower limb (finding)\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Finding of lower limb\Disorder of lower limb\Disorder of left lower extremity (disorder)\Injury of left lower limb (disorder)\Injury of left knee (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Finding of lower limb\Disorder of lower limb\Disorder of right lower extremity (disorder)\Injury of right lower limb (disorder)\Injury of right knee (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Finding of lower limb\Disorder of lower limb\Disorder of free lower limb (disorder)\Injury of free lower limb\Injury of knee\Injury of right knee (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Finding of lower limb\Disorder of lower limb\Disorder of free lower limb (disorder)\Injury of free lower limb\Injury of knee\Injury of left knee (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Finding of lower limb\Disorder of lower limb\Disorder of free lower limb (disorder)\Injury of free lower limb\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Finding of lower limb\Disorder of lower limb\Disorder of free lower limb (disorder)\Injury of free lower limb\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Finding of lower limb\Disorder of lower limb\Disorder of free lower limb (disorder)\Disorder of knee (disorder)\Injury of knee\Injury of right knee (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Finding of lower limb\Disorder of lower limb\Disorder of free lower limb (disorder)\Disorder of knee (disorder)\Injury of knee\Injury of left knee (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Finding of lower limb\Disorder of lower limb\Disorder of free lower limb (disorder)\Disorder of knee (disorder)\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Finding of lower limb\Disorder of lower limb\Disorder of free lower limb (disorder)\Disorder of knee (disorder)\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Finding of lower limb\Disorder of lower limb\Injury of lower limb\Injury of left lower limb (disorder)\Injury of left knee (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Finding of lower limb\Disorder of lower limb\Injury of lower limb\Injury of right lower limb (disorder)\Injury of right knee (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Finding of lower limb\Disorder of lower limb\Injury of lower limb\Injury of free lower limb\Injury of knee\Injury of right knee (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Finding of lower limb\Disorder of lower limb\Injury of lower limb\Injury of free lower limb\Injury of knee\Injury of left knee (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Finding of lower limb\Disorder of lower limb\Injury of lower limb\Injury of free lower limb\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Finding of lower limb\Disorder of lower limb\Injury of lower limb\Injury of free lower limb\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Finding of lower limb\Finding of knee region\Disorder of knee (disorder)\Injury of knee\Injury of right knee (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Finding of lower limb\Finding of knee region\Disorder of knee (disorder)\Injury of knee\Injury of left knee (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Finding of lower limb\Finding of knee region\Disorder of knee (disorder)\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Finding of limb structure\Finding of lower limb\Finding of knee region\Disorder of knee (disorder)\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees

\Musculoskeletal finding\Bone finding\Finding of bone of lower limb (finding)\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Musculoskeletal finding\Bone finding\Finding of bone of lower limb (finding)\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Musculoskeletal finding\Bone finding\Disorder of bone (disorder)\Bone injury\Avascular necrosis of bone (disorder)\Osteochondritis dissecans (disorder)\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Musculoskeletal finding\Bone finding\Disorder of bone (disorder)\Bone injury\Avascular necrosis of bone (disorder)\Osteochondritis dissecans (disorder)\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Musculoskeletal finding\Disorder of musculoskeletal system\Injury of musculoskeletal system\Bone injury\Avascular necrosis of bone (disorder)\Osteochondritis dissecans (disorder)\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Musculoskeletal finding\Disorder of musculoskeletal system\Injury of musculoskeletal system\Bone injury\Avascular necrosis of bone (disorder)\Osteochondritis dissecans (disorder)\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Musculoskeletal finding\Disorder of musculoskeletal system\Disorder of skeletal system\Disorder of bone (disorder)\Bone injury\Avascular necrosis of bone (disorder)\Osteochondritis dissecans (disorder)\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Musculoskeletal finding\Disorder of musculoskeletal system\Disorder of skeletal system\Disorder of bone (disorder)\Bone injury\Avascular necrosis of bone (disorder)\Osteochondritis dissecans (disorder)\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees

\Disease\Disorder of joint region\Disorder of knee (disorder)\Injury of knee\Injury of right knee (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of joint region\Disorder of knee (disorder)\Injury of knee\Injury of left knee (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of joint region\Disorder of knee (disorder)\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of joint region\Disorder of knee (disorder)\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Disease\Traumatic or non-traumatic injury (disorder)\Necrosis of anatomical site\Avascular necrosis of bone (disorder)\Osteochondritis dissecans (disorder)\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Disease\Traumatic or non-traumatic injury (disorder)\Necrosis of anatomical site\Avascular necrosis of bone (disorder)\Osteochondritis dissecans (disorder)\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Disease\Traumatic or non-traumatic injury (disorder)\Injury of lower limb\Injury of left lower limb (disorder)\Injury of left knee (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Disease\Traumatic or non-traumatic injury (disorder)\Injury of lower limb\Injury of right lower limb (disorder)\Injury of right knee (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Disease\Traumatic or non-traumatic injury (disorder)\Injury of lower limb\Injury of free lower limb\Injury of knee\Injury of right knee (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Disease\Traumatic or non-traumatic injury (disorder)\Injury of lower limb\Injury of free lower limb\Injury of knee\Injury of left knee (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Disease\Traumatic or non-traumatic injury (disorder)\Injury of lower limb\Injury of free lower limb\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Disease\Traumatic or non-traumatic injury (disorder)\Injury of lower limb\Injury of free lower limb\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Disease\Traumatic or non-traumatic injury (disorder)\Injury of musculoskeletal system\Bone injury\Avascular necrosis of bone (disorder)\Osteochondritis dissecans (disorder)\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Disease\Traumatic or non-traumatic injury (disorder)\Injury of musculoskeletal system\Bone injury\Avascular necrosis of bone (disorder)\Osteochondritis dissecans (disorder)\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of body system\Disorder of musculoskeletal system\Injury of musculoskeletal system\Bone injury\Avascular necrosis of bone (disorder)\Osteochondritis dissecans (disorder)\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of body system\Disorder of musculoskeletal system\Injury of musculoskeletal system\Bone injury\Avascular necrosis of bone (disorder)\Osteochondritis dissecans (disorder)\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of body system\Disorder of musculoskeletal system\Disorder of skeletal system\Disorder of bone (disorder)\Bone injury\Avascular necrosis of bone (disorder)\Osteochondritis dissecans (disorder)\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of body system\Disorder of musculoskeletal system\Disorder of skeletal system\Disorder of bone (disorder)\Bone injury\Avascular necrosis of bone (disorder)\Osteochondritis dissecans (disorder)\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of limb (disorder)\Disorder of lower limb\Disorder of left lower extremity (disorder)\Injury of left lower limb (disorder)\Injury of left knee (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of limb (disorder)\Disorder of lower limb\Disorder of right lower extremity (disorder)\Injury of right lower limb (disorder)\Injury of right knee (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of limb (disorder)\Disorder of lower limb\Disorder of free lower limb (disorder)\Injury of free lower limb\Injury of knee\Injury of right knee (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of limb (disorder)\Disorder of lower limb\Disorder of free lower limb (disorder)\Injury of free lower limb\Injury of knee\Injury of left knee (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of limb (disorder)\Disorder of lower limb\Disorder of free lower limb (disorder)\Injury of free lower limb\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of limb (disorder)\Disorder of lower limb\Disorder of free lower limb (disorder)\Injury of free lower limb\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of limb (disorder)\Disorder of lower limb\Disorder of free lower limb (disorder)\Disorder of knee (disorder)\Injury of knee\Injury of right knee (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of limb (disorder)\Disorder of lower limb\Disorder of free lower limb (disorder)\Disorder of knee (disorder)\Injury of knee\Injury of left knee (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of limb (disorder)\Disorder of lower limb\Disorder of free lower limb (disorder)\Disorder of knee (disorder)\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of limb (disorder)\Disorder of lower limb\Disorder of free lower limb (disorder)\Disorder of knee (disorder)\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of limb (disorder)\Disorder of lower limb\Injury of lower limb\Injury of left lower limb (disorder)\Injury of left knee (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of limb (disorder)\Disorder of lower limb\Injury of lower limb\Injury of right lower limb (disorder)\Injury of right knee (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of limb (disorder)\Disorder of lower limb\Injury of lower limb\Injury of free lower limb\Injury of knee\Injury of right knee (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of limb (disorder)\Disorder of lower limb\Injury of lower limb\Injury of free lower limb\Injury of knee\Injury of left knee (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of limb (disorder)\Disorder of lower limb\Injury of lower limb\Injury of free lower limb\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of right knee (disorder)\Bilateral osteochondritis dissecans of knees
\Disease\Disorder of limb (disorder)\Disorder of lower limb\Injury of lower limb\Injury of free lower limb\Injury of knee\Osteochondritis dissecans of bone of knee joint region (disorder)\Osteochondritis dissecans of left knee\Bilateral osteochondritis dissecans of knees

Status: current, Sufficiently defined by necessary conditions definition status (core metadata concept). Date: 31-Mar 2022. Module: SNOMED CT core

Descriptions:

Id Description Lang Type Status Case? Module

4946012018 Osteochondritis dissecans of bilateral knees en Synonym (core metadata concept) Active Entire term case insensitive (core metadata concept) SNOMED CT core

4946013011 Bilateral osteochondritis dissecans of knees en Synonym (core metadata concept) Active Entire term case insensitive (core metadata concept) SNOMED CT core

4946014017 Osteochondritis dissecans of both knees en Synonym (core metadata concept) Active Entire term case insensitive (core metadata concept) SNOMED CT core

4952805017 Osteochondritis dissecans of bilateral knee regions (disorder) en Fully specified name Active Entire term case insensitive (core metadata concept) SNOMED CT core

4952806016 Osteochondritis dissecans of bilateral knee regions en Synonym (core metadata concept) Active Entire term case insensitive (core metadata concept) SNOMED CT core

Expanded Value Set

Outbound Relationships	Type	Target	Active	Characteristic	Refinability	Group	Values
Bilateral osteochondritis dissecans of knees	Is a	Osteochondritis dissecans of left knee	true	Inferred relationship	Some
Bilateral osteochondritis dissecans of knees	Is a	Osteochondritis dissecans of right knee (disorder)	true	Inferred relationship	Some
Bilateral osteochondritis dissecans of knees	Finding site	Bone structure of left knee joint region	true	Inferred relationship	Some	1
Bilateral osteochondritis dissecans of knees	Associated morphology	Avascular necrosis	true	Inferred relationship	Some	1
Bilateral osteochondritis dissecans of knees	Finding site	Bone structure of right knee joint region (body structure)	true	Inferred relationship	Some	2
Bilateral osteochondritis dissecans of knees	Associated morphology	Avascular necrosis	true	Inferred relationship	Some	2

Inbound Relationships

Type

Active

Source

Characteristic

Refinability

Group

This concept is not in any reference sets