IPTC.
The newsroom's metadata: who took it, where, what is in it, and who may use it. Written in words rather than coordinates.
IPTC records are captions, credits, bylines, keywords, place names and copyright terms, standardised by the International Press Telecommunications Council. In a JPEG they arrive inside a Photoshop resource block: an APP13 segment whose payload begins with Photoshop 3.0\0.
What it is
Photoshop wraps several kinds of resource in that APP13 segment, and the IPTC-IIM record is the one that matters here. It stores fields designed for a photo desk — By-line, Credit, Caption, City, Country, Keywords — as plain text.
Why it matters
Where EXIF gives away a coordinate, IPTC gives away a sentence. A city name, a photographer's byline, or a caption written for internal use is often more directly identifying than a number, and it survives cropping, resizing and re-saving in most editors because those editors were built to preserve it.
captions, credits, location names. There is no partial mode: the resource block is dropped entire rather than edited, because editing metadata is a different and much larger problem than removing it.
Related terms
Common questions.
I need my copyright notice to survive.
Then ScrubPony is the wrong tool for that file. It removes; it does not edit or re-add. Scrub a copy for distribution and keep your captioned master.
Is IPTC the same as XMP?
No, though they overlap heavily and modern Adobe tools often write the same information in both. ScrubPony drops both.
Get ScrubPony
Strips identifying metadata out of JPEGs without touching a pixel. C99, no dependencies beyond libc, macOS and Linux, MIT-licensed.