Section 49
Previous bad character not relevant, except in reply
In criminal proceedings, the fact that the accused has a bad character, is irrelevant, unless evidence has been given that he has a good character, in which case it becomes relevant.
Explaination 1
This section does not apply to cases in which the bad character of any person is itself a fact in issue.
Explaination 2
A previous conviction is relevant as evidence of bad character.