1906 Postcard attachment, rated postage due.

1906 Montreal (Feb 4) with #89 1 Edward, newspaper attachment, rated 2c postage due. Rule 28 did not allow any attachment unless fully adhered. This was fully adhered, and should have been allowed at postcard rate but was rated as a letter, 2c, and 1c shortpaid, double deficiency, total 2c due.