What are these triangles for?

So, are the triangles just plain yellow or do they have a legend on them?

Could these signs be unique to Isle of Man? The Island is a Crown Dependency it has its own laws.

No Peter...see thumbnail at my initial post...plain yellow. The maker of these detailed models is one Gary Burns, & I can't locate him to ask my question of him
I've 4 or 5 WW2 British bomber airfields made by him & one included a model library so I'm able to use his objects on my airifelds, which is how I saw the Mob Store with yellow triangles. Maybe my question should be,what's a Mobility Store?

Ok...my typing error...but what is a Mobisisation Store? Do you know?

A mobilisation store would IMHO have things such as webbing, special types of clothing and all the stores for the field such as tents in it.

Well, that makes sense!! Thanks.