For example, I'll give you what makes me noticing that there's a problem when you don't make a search on keywords.
I've plenty of pictures with coconut trees (labeled "cocotier" in my pictures).
I always use captions to set my keywords because I find it way faster than using the dedicated keyword's tab.
So, for some pictures, I only set "cocotier" in the caption, and for others, I set many other thing, like "beach", "blue", "waves", etc.
When I want to make a search, if I check the "Whole word only" box and do a search with "cocotier", I'll get the pictures with only the word cocotier in the caption field, but not all pictures with the word cocotier.
I hope I'm clear...
If I uncheck the WWO box, I get the correct result, but it could be problematic to not use this option in some cases. (ex : you want to make a search on "car", but do not want "cartoons")
Actually, the whole word only behaves as if it was a "whole word only and nothing else in the field" option
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To add some more details, an "almost workaround" exists: by default, the iptc search box is set to "
with at least one of the words". If I set it to "
with the exact phrase", it works, even if WWO is checked. But it's a little bit restrictive because if you search more than one word it won't be useful.