Grok pattern to account for #

[Jim_Thunder]

I have log messages coming in and a few of them have one of three special characters: @, -, or #.

How can I get grok to ignore the hashtag without removing it from the new field? Below is the code snippet I'm using.

It works fine when it's just this:

(?<Tran_ID>[0-9A-Z@]{3,4})

But when I add the hasthtag, the rest becomes a comment:

(?<Tran_ID>[0-9A-Z@#-]{3,4})

[Badger]

Can you provide more detail? If I run

input { generator { count => 1 lines => [ '{ "id": "The id is A1#9" }' ] codec => json } }
output { stdout { codec => rubydebug { metadata => false } } }
filter { grok { match => { "id" => "(?<Tran_ID>[0-9A-Z@#-]{3,4})" } } }

then I get "Tran_ID" => "A1#9".