begin end Position Region 1 1 From what I can tell, feature instances in data whose position is to be defined using FALDO are always mapped to a Region, and then the position of this Region is defined according to its location within some larger reference sequence. The exception may be feature instances that are explicitly part of the reference sequence on which its location is being defined (such that no 'mapping' to a reference is required). This suggests that, conceptually, we can think of a FALDO:Region as a subregion of a reference sequence that is mapped to from a feature of interest, in order to define its position with respect to that reference sequence. A region describes a length of sequence with a start position and end position that represents a feature on a sequence, e.g. a gene. sequence_feature