X00 Subfield $j - Attribution qualifier:

Subfield $j contains attribution information for works for which the responsibility is unknown, uncertain, fictitious, or pseudonymous. Qualifiers should be used that follow the name of a known artist for the work.

Examples:

100 0#$aE.S.,$cMeister,$d15th cent.,$jFollower of

100 1#$aReynolds, Joshua,$cSir,$d1723-1792,$jPupil of