Hi, these wikidata id are used in some templates, such as in https://fr.wikipedia.org/wiki/Ligne_1_du_m%C3%A9tro_de_Sofia {notice there is still 2 and 4 missing, since there is a lag in the update process between OSM and wikipedia)

Bjr, il s'agit du numéro wikidata https://www.wikidata.org/wiki/Q123653112

Was a typo : the line currenty exists in fact

Didn't know that history checking tool, thanks

Sorry, it might be a typo.. better to change to "route_master" or "route", isn't it?

Administrative boundaries are boundaries therefore type=boundary seems logical.
Plus multilinestring appears to have a saying that ways aren't connected from start to end, whilst a boundary has necessarily a start and an end (there are of course exceptions but Andore//France appears to be straight boundary)
osm.wiki/Relation:multilinestring

It may perhaps be controversial but I prefer distinguish between master and child because they aren't obvious, so naming "route X" and "route X : from A to B" + "route X : from B to A" is more effective and prevents confusion in picking who is the master and who is the child

That's not the common practice : master route being 'route X' and child routes being 'route X :A > B" and "route X : B > A"
other examples : relation/6584634
relation/6584633
relation/2351006

Ok, I meant :relation/8708438 simply "Green line"
relation/3817120 being "Union depot >Target Field"
relation/3817130 being "Target Field>Union depot"

hi, because there is a master relationship being simply "green line" relation/8708438
having child going A to B and B to A