I came across the following letter in some documents I'm going through:
But I can't seem to find this letter in any IPA tables, nor can I find anyway to type this.
How can I find/type this letter?
What's it called?
The vertical short line marks a syllabic consonant -- when the nucleus of a syllable is a consonant. The interjection hmm in English might be transcribed [m̥m̩].
As the Wikipedia article notes, it's represented in Unicode with combining characters U+0329 ̩ combining vertical line below or U+030D ̍ combining vertical line above, depending on whether the IPA symbol it's attached to has a descender or ascender.