Inconsistency

Multiple types of functions/variables and casings makes the code unintuitive to parse and look for similar things.

Given the following function

void processVerificationRequest(request);

It should be intuitive that the function handling deletion requests would be called

void processDeletionRequest(request);

As opposed to processVerificationRequest and handleDeletionRequest for example, which makes no sense in the fact that their names don't necessarily imply they are related.