His first article, dedicated to professional guilds of medieval Islam, had been widely regarded as the most authoritative work on the subject for about thirty years.

While other subdivisions within tribes were possible, such as professional guilds ("colleges" or collegia), the tribe always remained the fundamental organizing unit.

Costumes worn by professional guilds are also called "Tracht".

However, the organization was not a professional organization and should not be confused with the professional guilds that emerge later.

Then he outlawed professional guilds, except those of ancient foundation, since many of these were subversive political clubs.

A PC is usually a member of a professional guild or a church following one of several gods.

An example of this is that certain professional guilds may disallow non-human members.

A professional guild (collegium) of musicians specialized in funeral music.

The buildings you see here are the collegia of the boatmen, professional guilds with considerable clout in Ostia.

Some of the khels were thus similar to professional or trade guilds.