Create a file x.vim containing only this line:
Now run ctags. The tags file is wrong.
The found tag is "x" (the character after the colon).
let y="a:test" -> tag "test"
let y="a:b:test" -> tag "b"
How I found it:
I have a file containing a line like this:
let &errorformat="%A%.%#rror reported by parser: %m"
Here ctags identified the tag " " (space), which
is also the char behind the colon. Then this entry is sorted to the top of the tags file (even before the comments).
Version: Exuberant Ctags 5.1
PS: Ctags is a GREAT tool!!