Thanks for the reply.  I don’t want to be overly critical because you have good intentions and want to do useful contributions, but there are more technical errors in the latest edits.  You’ve just created a new college named "Bâtiment Chambon".  This is incorrect.
A multipolygon is a relation that contains areas.  I know Chambon building but I don’t know exactly which part of the building hosts IHECS.  If you know that, the correct way to solve this is: either identify an existing area and add it to the multipolygon, or draw a new area with name=Bâtiment Chambon and add it to the multipolygon.  Tags about being a college should only be written once, on the multipolygon relation.
(I know this is maybe technical language here but OSM has a fairly elaborate data model if we want to show complicated structures correctly.)