Quote Originally Posted by Mikey_R View Post
The boss buff/debuff bars are slightly weird. They have a cap of 60 effects they can have on them at one time, however, it only shows the first 30. If your DoT happens to land in that second half, it's effects will still be applied, but you just cannot see them. If you refresh DoTs before they fall off, it just refreshes the timer, so they stayed hidden. If, however, you let the DoT fall off, you could reapply it and, if there was an 'empty' slot in the first 30, it would end up there and be visible again.

To my knowledge, the 'only show my DoTs' worked the same way. If your DoT happened to be in the first 30 on the list, it got displayed, of it was in the last 30, it wouldn't display, even if you had the option enabled (though I could be misremembering on that part).
Technically, the debuff cap is 200 (or was it 300?) but only on certain enemies (mostly Alliance raid bosses and Field Operation bosses do not necessarily count as such). The part about showing only 30 is true.

They increased it somewhere during ShB iirc and should be in one of the patch notes.