Technical Description of Software, as docu­men­ta­tion of the mecha­nism of its ope­ra­tion, requ­ires pre­ci­sion becau­se it con­sti­tu­tes docu­men­ta­tion of know-how (it can also be part of patent docu­men­ta­tion). Such docu­men­ta­tion can­not be sour­ce code of a spe­ci­fic (one of many on the mar­ket) pro­gram­ming lan­gu­age, as it must be a ​„dry” descrip­tion of the mecha­nism of ope­ra­tion, and not an exam­ple of one of many possi­ble imple­men­ta­tions. This is also poin­ted out by the author of the abo­ve-men­tio­ned book. Therefore, the docu­men­ta­tion of the sys­tem, it is not its exam­ple imple­men­ta­tion („wor­king code”), it is the essen­ce of its ope­ra­tion expres­sed as an abs­tract model.