WHMCS seem hell bent on not allowing HTML support, and in some ways I see why. However, it is most frustrating not to be able to emphasise some elements of a response that may contribute to making the ticket clear and concise.
May I suggest that a comprise is to allow a limited number of formatting codes like they do in the forums:
[ B ] for Bold [ /B ]
[ I ] for italics [ /I ]
[ U ] for underscore [ /U ]
These alone would be useful.
Soho.UK (London) : Soho.EU ( Amsterdam) : Soho.US (New York)