Comments in .htaccess must be on their own line, not appended to other statements.
The last rule doesn't work because the comments aren't really comments. Comments in htaccess must begin with a #
(must be at the start of a line), and not arbitrarily anywhere.
In the second case, the #bla bla bla
is interpreted as a 4th parameter of the RewriteRule
directive, which is simply ignored.
In the last case, the #bla bla bla
is interpreted as a 3rd parameter, which in the RewriteRule
's case is where the flags go, and #bla bla bla
isn't any flags that mod_rewrite understands so you get an error.