| Cartographic standards | Natural vegetation | Cultivated lands |

The Minimum Mappable Area is a concept applied by cartographers when determining the smallest area that can be shown on a map. This concept is therefore scale-dependent and not related to classification. LCCS 2.0 allows the introduction of the concept of a variable minimum mappable area.

Historically, the cartographer determined one particular minimum area to be represented on the map. This was applied to all classes contained in the legend. The disadvantage of this method is that classes with a difference in importance would follow the same rules. It would have been more logical to define a set of different sizes for the various features with differing importance (Di Gregorio, 1991).

The flexibility of the GLCN approach allows the introduction of the concept of a variable minimal mappable area. Thus, the user can relate the size of the minimal mappable area to the eight major land cover types from which the classes are derived.

Mixed Mapping Units allow the generation of mixed codes when saving a class from the classification to the legend module. This allows the user to develop a particular legend that reflects both parameters of scale and inherent characteristics of the area. LCCS 2.0 allows different types of mixed codes, with an exhaustive and codified syntax.

Two basic types of mixed coding are present:

• Thematic mixed coding
• Spatial (and/or time-related) mixed coding

Thematic mixed coding relates to a thematic uncertainty. It means that the specific polygon coded with the "thematic mixed code" cannot reflect unique thematic information (written A//B, implying "equal to A OR B", where A and B are land cover classes). It needs a certain level of generalization of the information. This syntax can be used only if the internal capabilities of generalization of LCCS are inadequate. In LCCS, in fact, the user has a certain possibility of generalizing the thematic class, meaning going from a more general to a more detailed level of class definition. If, for instance, the classifier Woody is used, this implies that an intricate mixture of trees and shrubs is present in which neither trees nor shrubs are clearly dominant. Thematic mixed coding, then, is an extra resource for the user to further generalize the thematic meaning of a class or for acting at a single-polygon level where, due to interpretation problems, a certain level of generalization is required.

Spatial mixed coding relates to the constraint of the scale when representing a geographical feature. It means that in the specific polygon coded Spatial Mixed, all the features are present but, due to the scale constraint (Minimum Mappable Area), they cannot be represented singularly (written A/B, implying "equal to A and B"). A Spatial Mixed Mapping code is always characterized by two or three (maximum) separate single land cover classes as defined in the classification system. The conditions governing the use of mixed mapping units are that within the minimum mappable area, two or more land cover classes are present, in a spatially separate entity (e.g. patches of agricultural fields inside a forest).
In this case, the general criterion proposed is that the cover of each one of the classes considered must be more than 20 percent (and consequently less than 80 percent) of the mapping unit. The limit of 20 percent is thus the threshold of "visibility" of a class in a Spatial Mixed Unit. The only exception to this rule is in the major land cover type Cultivated Areas, where the use of the option Scattered Isolated of the classifier Spatial Distribution goes from 10 to 20 percent. The sequence of the class names in a mixed mapping unit represents the dominance (e.g. for Forest/Cultivated Areas, Forest is more than 50 percent and less than 80 percent, whereas Cultivated Areas is less than 50 percent but more than 20 percent). A Mixed Mapping Unit can contain a maximum of three classes.

A variation of Spatial Mixed coding is the so-called "Layering". This situation applies when a feature belonging to Agricultural and Managed Area and another belonging to Natural Semi-Natural Vegetation occur in two separate strata (e.g. rainfed cultivated fields with open natural trees). For this specific case a different syntax is used (written A + B, implying "A and B layering").

Another particular case is "Time-Related" Mixed coding. This applies only to classes belonging to the major land cover categories Cultivated and Managed Terrestrial Area(s) (A11) or Cultivated Aquatic or Regularly Flooded Area(s) (A23), where the syntax is "A///B", indicating "A in one year; B in the other". Such coding is used to describe the situation where, in different years, different types of cultivation occur in the same field (i.e. the mapping unit).
This is the case when the user has, for example, a situation of cultivated fields of paddy rice in one year (e.g. when there is sufficient rainfall), followed by a terrestrial crop in a subsequent year (e.g. when rainfall is poor). This particular type of Time-Related Mixed coding shows often a cyclic, almost customary, alternation of different crops in subsequent years (e.g. generally an Aquatic crop followed by Terrestrial crops, or an Irrigated crop followed by Rainfed crops). It is important to note that the alternation of crops should be considered only when this occurs on an annual basis. The combination of different crops in the same growing period is an option already considered in LCCS class creation. However, because of the specific nature of this type of Mixed Unit, that occurs only where crops are growing, the classes composing such a mixed unit can only be those of Cultivated Area(s).