The term MCP is used both as a general term for all Microsoft Certified Professionals and as the name of a credential. As an MCTS, you become part of the Microsoft Certified Professional community, with access to all related benefits, information, and activities. You do not earn a credential titled "MCP." You should use the MCTS credential on your resume and in business collateral, thereby indicating your specialty and that you are a member of the MCP community at large.