Combinations of symbols

revision 01/00

The ISOM lays down the permissible combination of screens.

Forest runnable in one direction 411, use the appropriate rules from the main runnability colour,

Settlement 528, significant features must be shown for the yellow/green symbol, or the black line screen with no underlying detail should be used.

ISOM2000 increased the combinations allowed to 116, 210, 309, 310, 401, 402, 403, & 404 by allowing broken ground 116, uncrossable marsh 309 and open land 401 to be combined with some other symbols. The following table highlights the newly allowed combinations in red, for a view of the 1990 combinations click this link.

Permitted combinations

Newly permitted combinations

	Symbol Allowed with (new in *bold*)	Not allowed with
Broken ground 116	*310, 311, 401,* 402, 403, 404, 406, 407, 408, 409, 410	210, 309
Stony ground 210	*310,* 311, *401,* 402, 403, 404, 406, 407, 408, 409, 410	116, 309
Uncrossable marsh 309	**401, 402, 403, 404**	116, 210, 310, 311, 406, 407, 408, 409, 410
Marsh 310	*116,* *210, 401,* 402, 403, 404, 406, 407, 408, 409, 410	309, 311
Indistinct marsh 311	*116,* 210, 401, 402, 403, 404, 406, 407, 408, 409, 410	309, 310
Open land 401	*116, 210, 309, 310,* 311	402, 403, 404, 406, 407, 408, 409, 410
Open / scattered 402	116, 210, *309,* 310, 311	401, 403, 404, 406, 407, 408, 409, 410
Rough open land 403	116, 210, *309,* 310, 311	401, 402, 404, 406, 407, 409, 408, 410
Rough / scattered 404	116, 210, *309,* 310, 311	401, 402, 403, 406, 408, 407, 409, 410
Forest: slow 406	116, 210, 310, 311	309, 401, 402, 403, 404, 407, 408, 409, 410
Undergrowth, slow 407	116, 210, 310, 311, 403, 404	309, 401, 402, 406, 408, 409, 410
Forest: difficult 408	116, 210, 310, 311	309, 401, 402, 403, 404, 406, 407, 409, 410
Undergrowth, diff. 409	116, 210, 310, 311, 403, 404	309, 401, 402, 406, 407, 408, 410
Vegetation, fight 410	116, 210, 310, 311	309, 401, 402, 403, 404, 406, 407, 408, 409