How can I lock motion tracks so A doesn't select them?

I’m doing motion tracking (for my first time in Blender, so bear with me on the stupid stuff). Even if I lock a track with L, if I select tracks with A those tracks are still selected and have to be deselected (or the other tracks manually selected) for a new track to not overwrite what’s been done. How can I f’real lock a track so A doesn’t select it? (Or can locked tracks be hidden/unhidden?)

rwer

L key is a display.
Lock it up at Trek

Thanks–but that’s what I’ve been doing that still allows the tracks to be selected (It does say “locked” and the lock icon is highlighted).

Also, I just noticed that locking is an all-tracks thing, it doesn’t only lock the selected tracks. If it doesn’t prevent them from being overwritten, or from being selected, there’s nothing actually “locking,” so apparently L doesn’t really do anything. Then my question becomes: how can I get tracks actually locked?

I don’t know what it means. If you select Lock next to Track,
only that mark will be locked.