nbsps in titles

[ownedbycats]

Currently, nbsps in titles seem to be either stripped or converted to regular spaces. Is this intended?

Context: I have two fanfics titled Unknown. Usually, I title them "Unknown." (with period) so that the title would appear in book details. I thought an nbsp (U+00A0) at the end would work instead and be a bit less intrusive. It didn't work.

[JSWolf]

Titles don't have nbsps so no need for such.

[isarl]

Originally Posted by ownedbycats

Currently, nbsps in titles seem to be either stripped or converted to regular spaces. Is this intended?

Context: I have two fanfics titled Unknown. Usually, I title them "Unknown." (with period) so that the title would appear in book details. I thought an nbsp (U+00A0) at the end would work instead and be a bit less intrusive. It didn't work.

I think this is likely a result of Calibre's tendency to strip preceding and trailing whitespace from most fields when they are edited. I am not at my computer right now, but have you experimented with adding non-breaking spaces in the interior of a title and seeing if they are replaced? I would expect that they are not – but I also expect that your idea to use a trailing whitespace character will be unsuccessful no matter which whitespace character you use. (I would expect that Python's string.strip() method correctly handles all Unicode whitespace class characters equivalently.)

[theducks]

NBSP is not a valid file name character.
Not allowing, just saves the struggle to make a valid filename on ALL OS.

[isarl]

Originally Posted by theducks

NBSP is not a valid file name character.
Not allowing, just saves the struggle to make a valid filename on ALL OS.

While I definitely agree with the sentiment that NBSPs in filenames is not good practice, I am going to nitpick the broadness of your claims here. What constitutes a valid filename character depends on the filesystem. For example, NTFS uses Unicode to encode path names and does not prohibit nbsp characters.

Furthermore, as I understand them, OP isn't bothered if a title has nbsps replaced with ordinary spaces in the filename itself, and is instead mostly interested in tweaking the metadata in their Calibre library to distinguish a value of “Unknown” from the special value Calibre looks out for, which is that same string of “Unknown”, so that in the end, OP's custom “Unknown” tag appears in the tag browser instead of being ignored.

[ownedbycats]

Originally Posted by theducks

NBSP is not a valid file name character.
Not allowing, just saves the struggle to make a valid filename on ALL OS.

I expected it to just convert to an underscore.