Imifi is a Blend word from Imprimerie Industrielle et financière not a abbreviation to be writen with "." Also writen like that on the building and on BCE (0403.513.466 ) for the former  Public limited company who occupied the building. 

Outline is also not correct : https://www.openstreetmap.org/way/245010738 is a building part of the building.  See : https://www.ejustice.just.fgov.be/mopdf/2021/04/22_1.pdf#page=115

Main name seams to be : anciens bâtiments de l’Echo de la
Bourse , voormalige gebouwen van Echo de la Bourse But Imifi is still used too.
 



