The main core of SIGLE consists of a series of commands executed within AutoCAD. The corresponding programs are written in 'C', which in fact are no more than an 'extension' of AutoCAD. This means that they adhere to the language and the standard operations of AutoCAD. Area numbers and Area type. Automatic numbering (Prefix-Active) (Prefix = Floor, active = Area number). Insertion, suppression and modification are preserved within the drawing for future use.