125: Auto-increment track numbers
it's in the mass-tagging dialog, the tooltip for the button that allows you to complete all missing track number by incrementing the the track numbers of previous songs, or starting from 1
144: Can't create sink '{sink}' #what's the sink??
the sink is the term used by gstreamer when talking about output (here about audio output)
562: Reference point : #where is it?
titlebar plugin, to choose which window corner is used to position the overlay
815: argument {n} :
it's used in the new command preview of the nowplaying plugin, to show how the command line is broke into arguments
891: half-life
it's used in the weighted random configuration, to configure how fast the probability is dropping when the (for example) last played date gets closer to now
998: only show entries with at least n songs #maybe a '%' missing in front of n? Can't find it..
no the % is not missing

it's the tooltip at the bottom of artist/album/... lists (FPanes) the buttons at the bottom can be shown/hidden in the right-click menu
thinking about it, maybe replacing the n with the current number would be clearer. Suggestions for a better tooltip are welcome...
1076: use standard strftime variables
it's a new settings in the Misc. tab, the tooltip of the date format configuration
"man strftime" to get a description, I don't know if it has a better name, maybe "standard unix date/time format" ?
1095 & 1096 x/y offset
titlebar plugin how distance in horizontal/vertical pixels to put the overlay, relative to the reference point
btw, I'm very open to suggestions to improve the wording/spelling anywhere in gmb