8.1.2 When competing under these Regulations riders (other
than as provided in T.R. 8.1.8 and 8.1.9) shall wear
Club or Region registered design and colours, as is
appropriate.
8.1.9 In Road and Track events, Youth, Fourth and
Provisional category licence holders and BC non
licence holders will be allowed to wear any suitable
clothing whilst competing in events under the
Technical Regulations of the Federation, including that
bearing registered or unregistered advertising except
in the case of National Championships when they
must comply with T.R. 8.1.1 to 8.1.6. However
protective headgear must be worn.
So, you can wear what you like if you're a fourth cat or provisional.
Here we go, from BC rulebook.
8.1.2 When competing under these Regulations riders (other
than as provided in T.R. 8.1.8 and 8.1.9) shall wear
Club or Region registered design and colours, as is
appropriate.
8.1.9 In Road and Track events, Youth, Fourth and
Provisional category licence holders and BC non
licence holders will be allowed to wear any suitable
clothing whilst competing in events under the
Technical Regulations of the Federation, including that
bearing registered or unregistered advertising except
in the case of National Championships when they
must comply with T.R. 8.1.1 to 8.1.6. However
protective headgear must be worn.
So, you can wear what you like if you're a fourth cat or provisional.