What does “Vouch” mean?

A vouch is a public confirmation from other dealers that someone is legitimate and has traded honestly with them. In dealer groups, a vouch might be a post or comment along the lines of 'vouched, did a deal last month, smooth', and dealers with many vouches are seen as safer to trade with.

Vouches are useful but not foolproof. They are only as good as the people giving them, and they can be faked, exchanged between friends or based on small deals that say little about how someone handles a large one. A careful dealer looks at who is vouching, how recent and specific the vouches are, and whether they come from people the dealer knows personally. Withdrawing a vouch after a bad experience is a serious statement in the trade and is usually noticed quickly.

Example: 'Vouch for him, three deals this year, paid fast and the watches were exactly as described.'