Data in particular Data Classes is categorised according to 'type'. These types broadly correspond with fields in a normal database. Therefore, different fragments of text must be given types in order to become meaningful.
As an example:
Texttype: '32' - 'short_desc' might be a fragment of class text which is applied to short descriptions Texttype: '4' - 'interp' might be a fragment of class text which is applied to interpretations.