What was the design choice behind going with abbreviated URIs for topics (/t), and categories (/c), but using the full form for accessing user pages (/users)?
Because /users is a page on its own whereas /t and /c aren’t 
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The average end user isn’t aware of that though, just seems inconsistent.
The average end user isn’t looking at the location bar.
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Shorter URLs, less desire to “localize” URLs since they are not full words.
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Probably also because users don’t create super long URLs while topics do. I’m glad to have a convention that keeps these a bit shorter.
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We need /u/ for /users/ 
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This is now the case and implemented as /u/
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I can confidently say that none of my users are paying attention to that, lol.
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