I have always been using GTF and GFF files and discovered peculiarities as we go along. After all this years I realised that some information related to those formats sounded still mystic to me. Despite the different information available in many "official" places, some sides of the formats and especially the origin and the evolution of the differents flavors was still unclear. To disentangle everything I decided to make a comprehensive review of those formats. Even if this review has not answered all my questions that has been really informative and allowed me to (re-)discovered many useful information.
I guess this work can be useful for many of us, so here is the place to have a look at it: https://github.com/NBISweden/GAAS/blob/master/annotation/knowledge/gxf.md
Timeline of the different formats: