## 1 Introduction
It comprises: (i) a standard 3-level 8-class DP taxonomy of the Food and Agriculture Organization of the United Nations (FAO) Land Cover Classification System (LCCS) [16], see Figure 1, augmented with (ii) a thematic layer explicitly identified as class \"others\", synonym for class \"unknown\" or \"rest of the world\", which includes quality layers cloud and cloud-shadow. It is noteworthy that in traditional EO image classification system design and implementation requirements [17], the presence of an output class \"unknown\" was considered mandatory, to cope with uncertainty in inherently equivocal _information-as-data-interpretation_ (classification) tasks [18]. Figure 1 shows that the standard two-phase fully-nested FAO LCCS hierarchy consists of a first-stage fully-nested general-purpose, user- and application-independent 3-level 8-class FAO LCCS-DP legend, preliminary to a second-stage application-dependent and user-specific FAO LCCS Modular Hierarchical Phase (MHP) taxonomy, consisting of a hierarchical (deep) battery of one-class classifiers [16]. The standard first-stage 3-level 8-class FAO LCCS-DP hierarchy is \"fully nested\". It comprises three dichotomous LC class-specific information layers, equivalent to a world ontology, world model or mental model of the real-world [13; 16; 19; 20; 21; 22; 23; 24]: DP Level 1--Vegetation versus non-vegetation, DP Level 2--Terrestrial versus aquatic and DP Level 3--Managed versus natural or semi-natural. In recent years, the two-phase FAO LCCS taxonomy has become increasingly popular [25]. One reason for its popularity is that the \begin{table}
\begin{tabular}{c c} \hline
**Label** & **Classification** \\ \hline
0 & **NCDAN** \\
1 & **NCDAN** \\
2 & **DARS** \\
3 & **CICUDISHADONS** \\
4 & **VEGETATION** \\
5 & **BARE** \\
6 & **MNES** \\
7 & **CICUD LOW PROBABILITY** \\
8 & **CLOUD MEDIUM PROBABILITY** \\
9 & **CLOUD HIGH PROBABILITY** \\
10 & **THIN GRTRUS** \\
11 & **SNOW** \\ \hline \end{tabular}
\end{table} 
Table 1: Non-standard general-purpose, user- and application-independent European Space Agency (ESA) Earth observation (EO) Level 2 scene classification map (SCM) legend adopted by the sensor-specific Sentinel 2 (atmospheric, adjacency and topographic) Correction (Sen2 Cor) Prototype Processor [11; 12], developed and distributed free-of-cost by ESA to be run on the user side. \begin{table}
\begin{tabular}{c c c} \hline
**Original FAO** & **Label** & **“Augmented” FAO LCCS-DP taxonomy, class name** & **Pseudocolor** \\
**LCCS-DP Identifier** & & & \\ \hline A11 & 1 & Cultivated and Managed Terrestrial (non-aquatic) Vegetated Areas \\ A12 & 2 & Natural and Semi-Natural Terrestrial Vegetation \\ A23 & 3 & Cultivated Aquatic or Regularly Flooded Vegetated Areas \\ A24 & 4 & Natural and Semi-Natural Aquatic or Regularly Flooded Vegetation \\ B35 & 5 & Artificial Surfaces and Associated Areas \\ B36 & 6 & Bare Areas \\ B47 & 7 & Artificial Waterbodies, Snow and Ice \\ B48 & 8 & Natural Waterbodies, Snow and Ice \\  & 9 & Quality layer: Cloud \\  & 10 & Quality layer: Cloud–shadow \\  & 11 & Others (e.g., unknowns, no data, etc.) \\ \hline \end{tabular}
\end{table} 
Table 2: General-purpose, user- and application-independent ESA Level 2 SCM legend proposed in [13; 14; 15], consistent with the standard 3-level 8-class Food and Agriculture Organization (FAO) Land Cover Classification System (LCCS) Dichotomous Phase (DP) taxonomy [16]. The “augmented” standard taxonomy consists of the standard 3-level 8-class FAO LCCS-DP taxonomy (identified as classes A11 to B48) + quality layers Cloud and Cloud–shadow + class Others (Unknown) = 8 land cover (LC) classes + 2 LC classes (Cloud–shadow, Others) + 1 non-LC class (Cloud).