1) Double-click an item to open Media Item Properties
2) Click (not drag) on the volume fader
3) Sometimes, but not always, the fader moves down 0.05dB.
Why?
Also, on track volume faders (I always use the MCP for this):
1) Start with volume at 0.00dB
2) Ctrl+mousewheel (or whatever your preference) down one step at a time. It goes:
-0.06
-0.10
-0.15
-0.19
-0.24
and so on. Roughly but not exactly 0.05dB each step.
3) Now select multiple tracks, not with the same existing volume. Adjusting one of these tracks adjusts them by all exactly the same amount, which, because each step is not always exactly 0.05dB, means that one or more tracks may not land exactly on one of the values in the scale.
4) Click, not drag, on one of these volume faders and it always moves down to the next value in the scale.
Why? Does Reaper not like a track being at -0.23, or -0.14?
Hope all this all makes sense