The Molecular Signatures Database (MSigDB) is a collection of annotated gene sets for use with GSEA software. From this web site, you can

Prefix
msigdb
Alternative Prefixes
msig
Links
Homepage
Contact
Missing Contact
Pattern for Local Unique Identifiers

Local identifiers in Molecular Signatures Database should match this regular expression:
^M\d+$

Example Local Unique Identifier
M1   Resolve
Pattern for CURIES

Compact URIs (CURIEs) constructed from Molecular Signatures Database should match this regular expression:
^msigdb:M\d+$

Example CURIE
msigdb:M1
Contributors
Metaregistry Molecular Signatures Database

The metaregistry provides mappings between the Bioregistry and other registries. There are 2 mappings to external registries for this resource with 2 unique external prefixes.

Registry Name Registry Metaprefix External Prefix Curate
Biolink Biolink Model Registry logo biolink MSigDB
Integbio Integbio logo integbio nbdc02550
Providers

A provider turns a local unique identifiers from a resource into a URI. Many providers are also resolvable as URLs (i.e., they can be used in a web browser).

The local unique identifier M1 is used to demonstrate the providers available for Molecular Signatures Database. A guide for curating additional providers can be found here.

Name Metaprefix URI
Molecular Signatures Database msigdb https://biopragmatics.github.io/providers/msigdb/M1
Bioregistry bioregistry https://bioregistry.io/msigdb:M1