Art. 101 Ordinance of September 5, 1979, on Road Signage (OSR) - Principles
Art. 101 OSR · Principles
Signals and markings not provided for in the present ordinance are not permitted; exceptions are reserved for Articles 54, paragraph 9, and 115.
Signals and markings can only be installed or removed if ordered by the authority or the Federal Roads Office (OFROU); the procedure outlined in Article 107 must be followed.
Signals and markings must not be ordered or placed unnecessarily, nor should they be absent where they are essential. They should be arranged uniformly, especially on the same thoroughfare.
...
Signals apply to the entire roadway unless it is clearly indicated that they are intended only for certain lanes or special traffic areas, either by being placed above the roadway or due to specific arrangements (e.g., Article 59).
Signals should not follow each other at short distances.
Two signals may be installed on the same support; exceptionally and in compelling cases, this number can be increased to three; this principle does not apply to direction indicators. As a general rule, they should be placed from top to bottom: danger signals, regulatory or priority signals, information signals.
Signals may appear on a white rectangular panel: a. when placed above the roadway or above certain lanes; b. within localities when additional information is necessary; c. outside localities on less significant secondary roads (Article 22, paragraph 4) when additional information is necessary; d. on systems with variable signals. The additional information (e.g., an inscription, an arrow, a symbol) is black and appears on the white rectangular panel below the represented signal.
Signals in a luminous version may appear on black rectangular panels.
Yellow and black signals, with the exception of the "Main Road" (3.03) and "End of Main Road" (3.04) signals, are intended solely for military vehicle drivers. The signals have a yellow background; the border, inscription, and symbol are black. The provisions related to the protection of signals (Article 98 LCR) are applicable.
White and orange direction indicators show the direction to follow to reach educational centers, emergency medical posts, as well as relatively large public civil protection shelters that are difficult to identify without a direction indicator. The direction indicators have a white background; the border is orange and the inscription is black; the international emblem of civil protection may appear in an additional field at their base. The provisions related to the protection of signals (Article 98 LCR) are applicable.