Use Markers. Open the Marker List window (main menu, Options > Marker > Open List). Use the window's Options menu > Marker > Create to create as many Markers as you want. Click on the window's book-icon to flip to text-input mode, so you can type in any text you want. Use the same book-icon to flip back to the list again and pick the next Marker for text-editing. Make a Marker for lyrics, a Marker for mixer setup, one for special notes, etc... I just place them all in the first few measures of the song. The open Marker as Float function is very handy too.

Note that Markers with a length of 1 tick do get infinite length (well, until the end of song, that is). To have finite markers, give them any length > 1.