I'm not familiar with the specific meaning or context of "rct-514". This could potentially be:

1. A model number or part number for a product or equipment

2. An internal code or reference number used by a company

3. A designation in a particular field or industry

Without more context, it's difficult to provide a precise definition or explanation. If you have any additional information about where you encountered this term or what field it might relate to, I'd be happy to try and help further. Otherwise, you may need to provide more details from the source where you found this notation.