Site groups are orthologous positions in human, mouse, rat, etc. where phosphorylations or other PTMs occur.
Potentially could use a URI format like https://www.phosphosite.org/siteGroupAction.action?protOrg=1156&id=$1, but it's not obvious what the protOrg does.
phosphosite.sitegroup
Local identifiers in PhosphoSite Site Group should match this
regular expression:
^\d+$
Compact URIs (CURIEs) constructed from PhosphoSite Site Group should match
this regular expression:
^phosphosite\.sitegroup:\d+$