A precondition for assignment to this habitat type is the occurrence of the stated syntaxa on sands in the natural range of pine in conjunction with a large proportion of shrubby lichens.

New and recent plantations and non-natural pine forests are not assigned to this habitat type.

The habitat type is distinguished from the base-rich Peucedano-Pinetum steppe pine forests assigned to type 91U0 by the occurrence of acidophile dwarf vegetation and by the degree of coverage with shrubby lichens. Lichen-rich, acid-soiled Dicrano-Pinetum pine forests do, however, often have transitions to Peucedano-Pinetum steppe pine forests. In such cases, areas should be divided between the two habitat types based on the lichen coverage (drawing the line at 30 percent coverage). Where the two habitat types are closely intermingled, they should be mapped as a single complex and a percentage estimated for each type.

Transitions to habitat types 2310 and 2330 on inland dunes and type 4030 are included provided they still feature substantial occurrences of the tree and shrub species characteristic to habitat type 91T0.

Pine forests on coastal dunes are classified as habitat type 2180.

Advanced succession stages of once-open inland dunes can be assigned to this habitat type if the stated vegetation is present and the habitats are situated within the natural range of pine.

Adjoining dry margins should be included together with their vegetation when delineating the area.