Map references
 

Can anyone decypher the following RAF map references from 1939-40

They are most likely in Belgium or Holland, though NW France is an outside possibility.

Map H.5-80-3
Map I.17-26-3.5
Map I.19-292-2

Looking for the name of the nearest village or town to the reference

The last map reference might be 29.2, but it reads as 292 in the document

Any suggestions gratefully received

Martin