Dockpressing is the act of offering jobbing invitations at random, typically while standing around on an island's dock. The dockpresser may then offer permanent crew membership to anyone who accepted the invitation. This is typically done by small, inexperienced, or underhanded crews to take advantage of new players (greenies) and to artifically swell their ranks, thereby increasing the number of rogue marks they may receive, and fame they will generate.
Dockpressing is frowned upon by many players and by the Ringers.
Ways to discourage dockpressing
Officers who dockpress
Not everybody who dockpresses is deliberately circumventing the system. A surprisingly large number of captains and officers who dockpress do it because they believe that it's the only way to get jobbers and because they are unaware of the "hiring jobbers" button. Quite often a simple explanation of what is a much easier way to get jobbers is all it takes to prevent them from dockpressing in future.
Occasionally the officer may have complaints along the lines of "but nobody applies to my job offer", in which case it's often helpful to point out that engaging in a practice that many players find abhorrent and has been condemned by the Ringers is unlikely to enhance their reputation and improve turnout to their pillages.
It may also be helpful to check the dockpresser's crew information; quite often their captain will be most surprised to discover that an officer in their charge is dockpressing, and it may be a more effective form of punishment than verbal feedback or muting them.
If dockpressing is witnessed
If a player witnesses dockpressing in the same chat circle, a good solution is to loudly complain about dockpressers and explain why it's a bad idea to accept their offers. To put it simply, any crew that will hire any pirate they come across without sailing with them or even talking to them is probably just not that good. This provides the dual benefit of educating greenies and new players and discouraging them from giving into dockpressers, but may also dissuade the dockpresser himself.
If a dockpresser becomes abusive
The /complain feature can be used to deal with a dockpresser who becomes in any way abusive. While dockpressing in a vacuum is not complainable, abusive behaviour in any context is a whole other matter entirely. Note: as with any issue of abusive behaviour in-game, players should not attempt to provoke others into being abusive so that a complaint can be made. The Ocean Masters will see this provocation and may end up punishing both players!
The term dockpress probably comes from impressment, referring to "press-gangs" which would forcibly enlist sailors for a navy.