Transcription is both decoding and encoding; the text in the computer system will not be the same as the text of the primary source.
Accordingly, transcription of a primary textual source cannot be regarded as an act of substitution, but as a series of acts of translation from one semiotic system (that of the primary source) to another semiotic system (that of the computer). Like all acts of translation, it must be seen as fundamentally incomplete and fundamentally interpretative.
(Robinson et al. 1993, 21)