john89 wrote
Are those markings just an indicator showing that nobody is allowed to
cross the respective strip on the taxiway while the landing manoeuvre
is being carried out?

YES, an aircraft any closer to the runway centerline might disrupt the
radio beams for landing aircraft.

From the AIM:

k. ILS Course Distortion

1. All pilots should be aware that disturbances to ILS localizer and
glide slope courses may occur when surface vehicles or aircraft are
operated near the localizer or glide slope antennas. Most ILS
installations are subject to signal interference by either surface
vehicles, aircraft or both. ILS CRITICAL AREAS are established near each
localizer and glide slope antenna.

2. ATC issues control instructions to avoid interfering operations
within ILS critical areas at controlled airports during the hours the
Airport Traffic Control Tower (ATCT) is in operation as follows:

(a) Weather Conditions. Less than ceiling 800 feet and/or visibility 2
miles.

(1) Localizer Critical Area. Except for aircraft that land, exit a
runway, depart or miss approach, vehicles and aircraft are not
authorized in or over the critical area when an arriving aircraft is
between the ILS final approach fix and the airport. Additionally, when
the ceiling is less than 200 feet and/or the visibility is RVR 2,000 or
less, vehicle and aircraft operations in or over the area are not
authorized when an arriving aircraft is inside the ILS MM.

(2) Glide Slope Critical Area. Vehicles and aircraft are not authorized
in the area when an arriving aircraft is between the ILS final approach
fix and the airport unless the aircraft has reported the airport in
sight and is circling or side stepping to land on a runway other than
the ILS runway.



b. Holding Position Markings for Instrument Landing System (ILS).
Holding position markings for ILS/MLS critical areas consist of two
yellow solid lines spaced two feet apart connected by pairs of solid
lines spaced ten feet apart extending across the width of the taxiway as
shown. (See FIG 2-3-16.) A sign with an inscription in white on a red
background is installed adjacent to these hold position markings. When
the ILS critical area is being protected, the pilot should stop so no
part of the aircraft extends beyond the holding position marking. When
approaching the holding position marking, a pilot should not cross the
marking without ATC clearance. ILS critical area is not clear until all
parts of the aircraft have crossed the applicable holding position
marking.