The purpose of IPC-4761 is to provide PCB Designers, Fabricators and Assemblers with the latest information for protecting circuit board vias.
Bumped Via Protection
Hole plugging that protrudes above the surface.
Dimpled Via Protection
Fill material recedes below the hole interface.
Planarized Via Protection
Excess hole plugging or fill material protrude above the hole interface is removed.
Via Plugging Guideline
Technical article summarizing IPC-4761 specification, describing the via plugging process, and addressing the concerns of certain types of via plugs.