Does Exif metadata always get stored just after the JFIF header?

Question

In JPEG files, Does the exif metadata always gets stored as the first marker? Or it can be in between other markers?

The following has a comment that "After the APP1 Marker area, the other JPEG Markers follows." http://www.media.mit.edu/pia/Research/deepview/exif.html Is it confirmed?

Thanks

Answer 1

Specs (http://www.exif.org/Exif2-2.PDF) say that - yes - APP1 must come first, right after SOI (ffd8), but sometimes APP0 (JFIF) comes first, right before APP1. It cannot be considered as proper usage, since both specs - JFIF and EXIF state that corresponding markers should immediately follow SOI. But on practice it turns out that such cases happen pretty often, and image editors and viewers interpret such "non-proper" hybrid files correctly.