Yesterday I intended use the string h:m:s in my post. Didn't work because the forum software rendered the string as h
s
In other words: a small letter m between colons is rendered as
<img alt=":m:" class="emoji smilies" draggable="false" src="//cdn.jsdelivr.net/gh/twitter/twemoji@latest/assets/svg/24c2.svg"> or Unicode U+24C2 (CIRCLED LATIN CAPITAL LETTER M of Unicode block "Enclosed Alphanumerics")
Is this a bug or a feature?
I understand that BB smilies are generated by strings like :!: :idea: :o 8-) :) but a M or an A "smily" comes unexpected and I find such emojis a bit disturbing. I would expect that the BB software limits smily strings to those smilies that are presented in the right "Smilies" area of the editor. At least fake and real smilies can be disabled with the "Disable smilies" option.
[Edit] Oh well, it's a feature 
:snowman: 
:telephone: 
:skull: 
Found also a related thread: https://www.phpbb.com/community/viewtopic.php?t=2526111
To find out, which single characters are affected, here is a list of all ASCII characters enclosed in colons:
:":
:#:
:$:
:%:
:&:
:':
:
:
:*:
:+:
:,:
:-:
:.:
:/:
:0:
:1:
:2:
:3:
:4:
:5:
:6:
:7:
:8:
:9:
:::
:;:
:<:
:=:
:>:
:@:
:A:
:B:
:C:
:
:E:
:F:
:G:
:H:
:I:
:J:
:K:
:L:
:M:
:N:
:O:
:
:Q:
:R:
:S:
:T:
:U:
:V:
:W:
:X:
:Y:
:Z:
:[:
:\:
:]:
:^:
:_:
:`:
:c:
:d:
:e:
:f:
:g:
:h:
:i:
:j:
:k:
:l:
:n:
:
:p:
:q:
:r:
:s:
:t:
:u:
:w:
:
:y:
:z:
:{:
:
:}:
:~:
can't be generated via colon code because 
