An identifier scheme defines a set of identifiers that can be used to describe things together with the rules on how to create and manage them. In the context of the capability meta-data they are used for the identification of participants, processes and services / documents.
For the correct operation of an SMP server the only relevant aspect of the identifier scheme is whether the identifiers defined by it are case sensitive or not as this impacts how queries need to be processed. Therefore the meta-data of identifier schemes maintained in Holodeck SMP is limited to the identifier of the scheme itself, the name of the scheme and the organisation that governs the scheme.
Identifier schemes can be managed by clicking on Settings and selecting the ID Schemes tab. Note that once an identifier scheme is saved its identifier cannot be changed anymore.