The RTM "Smart Add" feature allows you to add or create a tag for a task by using the "#" character in front of the required tag name when you forward an email to RTM - this is fine.
However the same thing happens when you convert a Gmail into a task when using the Gmail add-on - this is not necessary as with the add-on you can directly select the required tag(s) from the side bar drop down.
I only noticed this because I received an email regards a delivery from Amazon and the email subject line included the order number precluded by the "#" character (American shorthand for "number").
When I used the Gmail add-on to turn the email into a task it all worked fine except it created a new tag from all the text following the "#" and removed this text from the subject of the task - obviously not fine.
I suspect the same thing would happen if the subject line of the email contained any of the other Smart Add characters (! * =) but have not tested it.
Can RTM confirm this is what is happening and that it will be looked into please.