Control description categories: Column C | Column D (Landforms; Rock and boulders; Water and marsh; Vegetation; Man-made features; Special items) | Column E | Column F | Column G | Column H | Special instructions

Column D indicates the feature on which the control flag is placed. These are cross-referenced
to the ISOM 2017-2 (International Specification for Orienteering Maps) and ISSprOM 2019-2
(International Specification for Sprint Orienteering Maps)
symbol or symbols used to represent
them (which are generally harmonised). Note that where a number is given it includes all symbols
beginning with that number (e.g. 509 indicates 509.1 & 509.2).

If a second control feature is required (i.e. for crossing; junction; between) then this must go in
column E. It is not permitted to place two symbols in Column D.

Rock and boulders (ISOM / ISSprOM section 3.2)

Ref.SymbolNameDescriptionISOM/ ISSprOM
2.1CLIFF, CRAGA cliff or rock face. May be passable or impassable.201
2.2ROCK PILLARA high, natural rock projection.206
2.3CAVEA hole in a rock face or hill side, often leading to underground workings.203
2.4BOULDERA prominent free-standing block of rock or stone.204
2.5BOULDER FIELDAn area covered by so many boulders that they cannot be individually mapped.208
2.6BOLDER CLUSTERA small distinct group of boulders so closely clustered together that they cannot be individually mapped.207
2.7STONY GROUNDAn area covered with many small stones or rocks.210
2.8BARE ROCKA runnable area of rock with no earth or vegetation cover.214
2.9NARROW PASSAGEA gap between two cliffs or rock faces that face each other.201
2.10TRENCHA rocky or artificial trench.215