In ArcGIS Enterprise, the default Username is the first part of the email address.
Please add a new option in "Settings/New members default" to change the naming pattern.
This would be especially useful for "builtin user" management.
Allow the variables such as:
%longfn% -> john
%longln% -> doe
%shortfn% -> j
%shortln% -> d
%emailname% -> j.doe
%email% -> j.doe@new-company.com
%u% -> next letter is uppercase
%shortorg% -> nc
%longorg% -> new-company
%counter% -> increasing number for each new user
So the following would be possible:
%longfn%.%longln%%counter%
john.doe01
jane.hill02
or
%shortfn%%shortln%%counter%
jd01
jh02
or
%email%
j.doe@new-company.com
j.hill@new-company.com
This would be especially useful for SAML Accounts that use the full email address. This way, adding new users via Portal would be easier, as the Username would be correct by default.