A flag to indicate the scope of the alignment between the sequence of the entity or biological unit described in the data block and the referenced database entry. 'entire' indicates that alignment spans the entire length of both sequences (although point differences may occur, and can be annotated using the data items in the STRUCT_REF_SEQ_DIF category). 'partial' indicates a partial alignment, and the region (or regions) of the alignment may be delimited using data items in the STRUCT_REF_SEQ category. This data item may also take the value '.', indicating that the reference is not to a sequence.