The libelle_association_mots
pipeline is called in ecrire/exec/mots_tous.php to display the text description of the elements that can be linked to a given keyword group. Each object is associated with a language string identifier:
$libelles = array(
'articles'=>'info_articles_2',
'breves'=>'info_breves_02',
'rubriques'=>'info_rubriques',
'syndic'=>'icone_sites_references'
);
$libelles = pipeline('libelle_association_mots', $libelles);
So the pipeline is passed an associative array with keys being the object names (written in the plural) and values being the names of the corresponding language string identifier.