Certain attachments, such as logo files or social media icons can appear repeatedly in your descriptions and notes, especially if included in the signatures of your users. You have the ability to identify the attachments you want to block from processing.
Additionally, if a file comes through that you want to block going forward, you can quickly block it right from the issue screens. When viewing the issue, you can click on attachments in the left menu, the paper clip icon by the issue number or scroll to the attachment list on the issue. Next to each attachment will be a block link. Clicking that will add that particular attachment to the blocked list.