Tags were originally envisioned as a pretty simple way to group subscribers by a characteristic (say, where they came from or what they're interested in.) While they're still great for that purpose, we've found that many of our customers have been using them in more complex ways more akin to multivariate data in order to power automation flows or high-octane template personalization.
Even the very newsletter we use to send folks updates about Buttondown is starting to do this! We've got tags for each kind of plan someone could be on, as well as features that they're using — so we can send relevant information to the right people.
This many tags gets a little unwieldy when you're trying to browse through them en masse. So we've made the various tag inputs a little smarter: if you declare tags in a "key:value" syntax (like we do above), Buttondown now will now automatically group them in the UI to make things a little easy to parse.
Here's that same list of tags from above, but in the UI:
This is the first of a few changes we have planned to make managing large numbers of tags easier. The goal here is graceful enhancement: adding opt-in features that make the product better for folks who need them, without making the product more complex for folks who don't. Hope you love it!