The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Plants (2 members)
- Plastics (2 members)
- Police (2 members)
- Polish (3 members)
- Pootle (1 member)
- Portuguese (1 member)
- Printing (7 members)
- Prisma (1 member)
- ProZ.com KudoZ (1 member)
- Procurement (3 members)
- Procurementportal.com (1 member)
- Property (5 members)
- Proz.com (3 members)
- Public procurement (1 member)
- Pumps (5 members)
- Puzzelwoordenboek (27 members)
- Quanjer (1 member)
- R-Phrases (2 members)
- REHVA (2 members)
- Railway (17 members)
- Rangtelwoorden (1 member)
- Refrigeration (1 member)
- Religion (2 members)
- Resources (0 members)
- Resources for translators (1 member)
- Reverse engineering (1 member)
- Rijnland (1 member)
- Risk phrases (2 members)
- Romanian (1 member)
- Russian (2 members)
- SAP (3 members)
- SCC (1 member)
- SEO (4 members)
- Sailing (1 member)
- Scaffolding (2 members)
- Scanned (0 members)
- Scanning (0 members)
- Schiphol (1 member)
- Scripting (1 member)
- Sentences (1 member)
- Serge Braudo (1 member)
- Service Level Agreements (1 member)
- Sewing (3 members)
- Shipping (5 members)
- Shoe sorters (1 member)
- Signal words (1 member)
- Slovenian (1 member)
- Software (26 members)
- Solar energy (1 member)
- Spanish (5 members)