Sometimes you may end up with several note types of the same name. This usually happens due to importing multiple decks, although you can also create a note type with the same name as another one in the Manage Note Types dialog box.
While this is generally harmless, it can be somewhat annoying if you can't tell which cards belong to which note type, so you can fix it as follows:
- First, confirm that all of the note types with duplicate names are really the same by going to the browser, clicking on each one in turn, and comparing the fields that are shown at the bottom of the window. (If you're not sure, you can also click the Cards button and make sure that the templates are the same as well.) If they're not the same, you should use the Manage Note Types dialog (mentioned in step 2) to rename one to something else instead.
- In the main Anki window, choose Tools → Manage Note Types. Select one of the duplicate note types, click Rename, and give it a new name (you can change it back later if you wish).
- Open the browser and click on one of the remaining note types with a duplicate name. Select all the cards, choose Edit → Change Note Type, and select the note type you just renamed for "New note type." Repeat this step as necessary.
- Close the browser, go back to the Manage Note Types dialog box, and delete the now-unused note types. If you wish, you can change the one you renamed in step 2 back to its original name.