To create a set of approved Tags, go to Settings -> Customizations
By default there will be no Approved tags which means any arbitrary tag can be created and used.
To create a list of approved Tags, namely, the set of Tags that can be applied to vendors and will show as Tag filters click the blue pencil icon.
Then add your list of Approved Tags. In the example below we added three tags (Tag1, Tag2, Tag3). Once saved these are the only tags that can be used.
In your global Vendor list, if you choose a vendor you will see the only allowed tags in their vendor record are the ones we created above in the Approved Tags configuration.
The Approved Tags are also the only ones that will be visible in your global vendor list Tag filter.
