In a note in Turtle (CR) it says:
Prefixed names are a superset of XML QNames. They differ in that the local part of prefixed names may include:
- leading digits, e.g.
leg:3032571
orisbn13:9780136019701
- non leading colons, e.g.
og:video:height
- reserved character escape sequences, e.g.
wgs:lat\-long
→ Reserved character escape sequences
[…] consist of a '\' followed by one of
~.-!$&'()*+,;=/?#@%_
and represent the character to the right of the '\'.
So it should be possible to use:
dbpedia:Jesuit_Church\,_Mannheim