Question juridique clé
Whether the appellants had standing under Art. 89 LTF to challenge the planning convention amendments.
Solution extraite
They lacked standing because the convention bound only the authorities and did not directly affect private owners' rights; any participation rights could be asserted later in the planning procedure.
Motifs extraits
The appellants were not particularly affected in a personal interest distinct from the general public. The convention merely coordinated municipal planning and produced no direct obligations or rights for private persons.