One main challenge is that IGT encodings in L A T E X documents may contain arbitrary T E X and L A T E X macros from various sources, including (a) standard macros for font styles, citations, footnotes, cross-references or even lowlevel formatting instructions, (b) macros from imported packages, like tipa 5 for phonetic symbols or leipzig 6 for standard glossing abbreviations, and (c) additional userdefined macros of arbitrary complexity, as illustrated in Figure 4.
robust extraction of IGT data from L A T E X documents is only possible on the shoulders of a full-blown T E X parser.