From the other side of this, I'd rather that people set to not see NSFW work (e.g. guests) didn't see a bunch of CONTENT WARNINGs either. With FA, a guest stumbling across my page sees all the SFW stuff. With FN, the options are they see a big "guests blocked" banner, or a bunch of "oh boy this sure is weird porn" warnings amongst the SFW content.
I'm now seeing the error message, but the title length limit is even lower than FA's. :/ Pretty restrictive!
This would be awesome for variants. FA tends to end up with people hosting them off-site, which sucks for a huge number of reasons.
Indeed, rather than compare images, it's possible to just compare submission IDs, assuming FN stores the FA ID an image was imported from (I really hope it does!). Then this becomes a lazy as-others-import operation, same as how follows can synced as and when the people who follow import.
The FA importer keeps underscores as-is, so that's probably one huge source for it. FA tags may also use dashes, so there's some sense in normalizing those, but beware mangling things like "semi-skimmed_milk".
(Aside: the real tragedy in FA tag import is losing that FA tags are ordered, so using them as sideband jokes just turns into noise. ;_; )
The other advantage of ID-first is that sorting by name will sort them correctly by upload order, at least assuming it's some kind of incrementing field.
See also Twitter for doing this.
If you want to be really awesome, expose an API to access it, with OAuth for letting people log in to see protected content.
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