Cześć (switching to English in three, two, one... :) ),

25. LOC Switch
When pushed, the LOC switch arms the AFDS to capture and fly the localizer front course. The switch must be pushed prior to localizer capture.
LOC is displayed in white on each ADI prior to capture.
The localizer will not capture if the intercept angle is greater than 120 degrees or 2.5 NM.
The current lateral nav mode (LNAV, heading select, or heading hold) remains engaged until localizer capture.

It seems that it only works with localizers (and not even BC), which would be right, cause as far as I know modern acfts don't have VOR capture capabilities. I'll fly around and see for myself. Stay tuned.

EDIT: OK, a little update. I've flown a bit around EPWA with OKE radial 309 outbound - doesn't work at all. Can't even hold the course. I guess it's all the way it's supposed to be. I own the MD-11 from You-Know-Who and she has no VOR LOC too - life.