Through the Moodle interface (standard Group/Grouping management page) a user can create a group with a name that includes a colon. If the csv file for the user enrol plugin contains this same group name (with the colon), then the upload fails. This error is shown: Line 2: Unable to parse the line contents 'test@test.ac.uk,test:test'

I then tested this with a whole host of characters and most of them fail (I do not know which are accepted through the standard interface).

Line 2: Unable to parse the line contents 'test@test.ac.uk,test:test'
Line 3: The user test@test.ac.uk cannot be enrolled because they do not yet have an account in Moodle (this was the character - )
Line 4: Unable to parse the line contents 'test@test.ac.uk,test=test'
Line 5: Unable to parse the line contents 'test@test.ac.uk,test*test'
Line 6: The user test@test.ac.uk cannot be enrolled because they do not yet have an account in Moodle (this was the character &)
Line 7: Unable to parse the line contents 'test@test.ac.uk,test^test'
Line 8: Unable to parse the line contents 'test@test.ac.uk,test%test'
Line 9: Unable to parse the line contents 'test@test.ac.uk,test$test'
Line 10: Unable to parse the line contents 'test@test.ac.uk,test�test'
Line 11: Unable to parse the line contents 'test@test.ac.uk,"test""test"'
Line 12: Unable to parse the line contents 'test@test.ac.uk,test!test'
Line 13: Unable to parse the line contents 'test@test.ac.uk,test:test'
Line 14: Unable to parse the line contents 'test@test.ac.uk,test#test'
Line 15: Unable to parse the line contents 'test@test.ac.uk,test~test'
Line 16: Unable to parse the line contents 'test@test.ac.uk,test]test'
Line 17: Unable to parse the line contents 'test@test.ac.uk,test[test'
Line 18: Unable to parse the line contents 'test@test.ac.uk,test}test'
Line 19: Unable to parse the line contents 'test@test.ac.uk,test{test'
Line 20: Unable to parse the line contents 'test@test.ac.uk,test;test'
Line 21: The user test@test.ac.uk cannot be enrolled because they do not yet have an account in Moodle (This was the character ')
Line 22: Unable to parse the line contents 'test@test.ac.uk,test@test'
Line 23: Unable to parse the line contents 'test@test.ac.uk,test>test'
Line 24: Unable to parse the line contents 'test@test.ac.uk,test Line 25: Unable to parse the line contents 'test@test.ac.uk,test?test'
Line 26: Unable to parse the line contents 'test@test.ac.uk,test/test'
Line 27: Unable to parse the line contents 'test@test.ac.uk,test\test'
Line 28: Unable to parse the line contents 'test@test.ac.uk,test|test'
Line 29: Unable to parse the line contents 'test@test.ac.uk,test�test'