memberUid

memberUid is an LDAP attribute used to enumerate the user identifiers that belong to a POSIX-style group. It is commonly defined in the posixGroup object class as part of RFC 2307 schemas. The attribute is multi-valued and stores identity strings that correspond to user accounts’ login names (the UID), such as alice or jdoe. Unlike membership attributes that store full distinguished names of user entries, memberUid holds simple UID strings.

Usage and scope

memberUid is used to represent group membership in environments that follow UNIX and POSIX conventions. In a posixGroup entry, each member is added as a separate memberUid value. This approach aligns with traditional UNIX group representations where the essential identifier is the user’s UID.

Format and constraints

Each value of memberUid should match the uid attribute of a corresponding user entry. LDAP servers do not inherently enforce this cross-reference, but administrators can implement validation or tooling to maintain consistency. memberUid is typically a string-type attribute and is considered a multi-valued attribute.

Example

dn: cn=developers,ou=Groups,dc=example,dc=com

objectClass: posixGroup

gidNumber: 1001

memberUid: alice

memberUid: bob

Relation to other attributes

Some schemas use groupOfNames (which stores DNs in the member attribute) as an alternative to memberUid. RFC 2307-based setups commonly prefer memberUid for POSIX compatibility, while other directory schemas may use different membership representations.

See also

posixGroup, uid, RFC 2307, group membership attributes, member (DN-based).