Hi bud
Not my area of expertise.... but, if the tile is above a specific size they need to have a form of mechanical fix back to the substructure or frame.... various options to achieve this, if the supplier is reputable they will advise
Slip bricks actually fall out if the above as they are smaller in size (individually), but guidance then calls for a form of mechanical trim within the grout lines horizontally to stop the shear in the adhesive. this is usually for domestic and not really high rise applications...
That said, most brick system suppliers usually supply the clip slips to backer frame for high level systems... safer than the risk of adhesive failure ....
Go search the Tile Association for specific guidance and link to the regs
hope this helps
