So I have written and published a wordpress plugin. Once I submitted it to wordpress.org to be included in the repository I noticed that the tag is wrong. However I can't find anywhere how to change it. can anyone help?
You can change tags in your readme.txt file. Then you have to upload it again via SVN to the Plugin Directory. I recommend you to do that when you will be about to release a new version of your plugin (people don't like frequent updating, especially if they do not get any extra features with every update).