That is an interesting puzzle, Koen.
I tried your search in my own library and found that roughly 10% of my pictures show up, when I search for "unid" with "Text includes", but I do not see this string in any of the EXIF or IPTC tags, just like you. The funny thing is, I find exactly the same images, if I use the search rule "Place includes unid".
The result are images from the United States, Spain, Australia, Great Britain. None of the place names includes this string.
So I suspect, the string is hidden in the "Places" representation in the versions inside Aperture. I searched the original master files and the exported versions with exiftool, strings, grep and could not find the string "unid" anywhere.
Do your "unid" pictures also have places assigned?
"Place" was next on my list .
In one of my Libraries in which I use Places, if I filter for "Place" "is empty" it get 2790 items. These are the same 2790 items that _do not show_ if I filter for "unid". From this I conclude that the string "unid" is added to Images which have a Place assigned, and that the text filter includes whatever field in which "unid" is written.
I don't have time to do any further testing right now.
Koen -- why did you filter for "unid"?
These are the same 2790 items that _do not show_ if I filter for "unid".
exactly - I have only one image that does show for the combined search "Place is empty" and "Text includes 'unid'", and this image has an IPTC tag: "Image City: Comunidad Yumani, Isla del Sol"
Pure speculation: "unid" is a very common shortcut for "unique document identifier" or "unique image ID". Perhaps the "Places" database references "unid" tags to places objects.
I am glad you also find some unexpected behaviour when filtering for 'unid'. But your findings differ a bit from mine, as all of the images which are returned upon filtering for 'unid' have places assigned to them.
What I have found is that all images which unexpectedly show up are TIFF's which are created from RAW and edited in an external editor. The TIFF do not have the keyword 'unid' to them, but the RAW does (attaching the keyword 'unid' is part of my imprt process). After editing the image in the external editor the keyword 'unid' is removed from the TIFF and replaced by other keywords. In the unexpected cases I forgot to remove the keyword 'unid' from the original RAW file. The full text search filter with 'unid' does definitely return the TIFF's however, not the RAW files.
Strange is that after I discovered this I removed the keyword 'unid' for the RAW files, but nothing changes. The TIFF's still show up, even after the keyword 'unid' has been removed from the corresponding RAW file.
I use the keyword 'unid' as a keyword for 'unidentified species' (of insect).
I created a new library, imported two JPG pictures with keyword 'unid'.
Picture 1 edited with BorderFX, removed 'unid' from resulting TIFF
Picture 2 edited with Noise Ninja, removed 'unid' from resulting TIFF
Now filtering with 'unid' returns picture 2 TIFF, but not picture 1 TIFF (and both imported JPG's)
edit: all images (JPG's and TIFF's have places assigned, JPG's already on import)
So (briefly) you have a solution, though it is a bit of work-around. The string "unid" should be reserved by Aperture and should not be available as a Keyword. Change your Keyword. I find the auto-fill feature for Keywords very useful (it keeps me from making spelling errors). Instead of something different (e.g. "NotID"), you can simply add to the string you already use. Perhaps "unid'd"? Since, after the change, "unid" will not be a Keyword, anytime you type "unid" (or perhaps even "uni"), Aperture should auto-complete to "unid'd". (Apostrophes are just another character to the Keyword parser.)
I find it helpful to capitalize all my Keywords (e.g. "Portrait", not "portrait"). I then input Keywords by typing in lower case, and let auto-complete fill in the Keyword and change the capitalization. Periodically I open the Keyword HUD to look for problems. Using this system, every Keyword that is not capitalized indicates a problem.
The "unid" text search result is clearly (imho) a bug. You should report it to Apple: "Aperture➞Provide Aperture Feedback".
Do you have "unid" assigned to a Keyword button? If so, you should remove it from the button before you change or delete it from your Keyword HUD. Keywords assigned to buttons persist even if they are removed from the Keyword HUD.
Message was edited by: Kirby Krieger
Leonie, in your post you said you came up with an image with an IPTC tag - "Image City: Comunidad Yumani, Isla del Sol"
ComUNIDad does have unid in it.
Did a few more experiments. Do you guys find that if you put the whole string "unidos" in the search, you get the same images appearing? Or communidad for that matter.
Seems like if you've dragged an image to a Place that, in Spanish, has the word unidos in it, it will appear in any search with unid. The United States is Estados Unidos in Spanish. Photos dragged to places in the UK may also appear, United Kingdom, etc.
That's as far as I've gotten at this point...