ILS Critical Area signage: Localizer or Glideslope?

Hi,

Does the ILS Critical Area sign apply to the localizer or the
glideslope antenna? Or is this is a dumb question?

CCR (Concord California) 19R has a localizer approach. No glideslope.
It has an ILS Critical Area sign. I read recently that ILS
equipped fields require the ILS critical area sign for the ground
based Glideslope antenna. Apparently, a portion of the glideslope
signal is bounced onto the ground, thus the requirement of not parking
a vehicle in that area.

AK (with too much taxi time)