Sometime campaigns name don't convey all the information you want for a campaign. That's where Tags come in handy. 

Setting tags allow you group campaigns together and show up in the search box of the campaign manager. 

Setting a tag is easy. Open the campaign in the Campaign Manager. Click the Tags box and type a tag followed by a comma and then the next tag (if required). There is no limit to amount of Tags you can set.  

To delete a tag - simply click the X in the tag. Everything is saved automatically. 

Tip: When using the API call /campaign tags are included in the list of campaigns returned.