[flexxaeon]

Client owns the project and codebase, particularly if they paid for it. Developer does not have the right to take that code and resell/re-use, but it would be really difficult for client to enforce or restrict a freelacer from using "snippets".

[byoung2]

He should write into the MSA that he has a standard library of code snippets already written that he plans to incorporate into the finished work, and clearly label these in the codebase with an explicit license.