X, the company formerly known as Twitter, is struggling to establish its new name and is in fact still frequently referred to as just that: X, formerly known as Twitter. The problem with a single letter brand, and X in particular, is that it already has many wide-ranging meanings. X is the Roman numeral ten, the multiplication symbol, and shorthand for a kiss. It can serve as a signature. It “marks the spot,” checks the box, and crosses out. It can connote caution, as in poison (three Xs) or X-rated content, or the unknown, as in Mr. X.

As part of a longer brand name it can work, as in Xbox, the X Games, or even SpaceX. But by itself, it’s generic, as in Brand X.

With all its meanings, X appears on the surface to have nothing to do with a social media company, while its previous name, Twitter, was easily understood to be about communicating. Which is why it’s hard to fathom what owner Elon Musk was thinking when he announced the re-brand. This is not to say that Twitter is the best brand name ever, but it was well-established, it had relevant meaning, and it had brand equity. Mr. Musk may have felt that Twitter carried baggage of some kind or that X fit his loosely stated vision to broaden the brand to include a range of services, like a digital wallet.

So what are some criteria for changing a brand name, a process that sounds simple yet is anything but? Here are a few:

Your brand name has not transitioned well to changing times: Kentucky Fried Chicken sought to get away from “Fried” by changing its name to KFC. Is their chicken still fried? Yes, but at least it’s not in their brand name anymore.

Your brand name is limiting. It could be a local name that was a great focal point at the start but has become a drag on expansion, like using the nearest city in your brand name. Years ago, a brand named Just Cabinets had early success but found it hard to add other product lines. They became Just Cabinets & More and then Just Cabinets Furniture & More but failed to balance a specific product focus with a much more general one.

Your brand is expanding its reach. Mergers, geographic expansion, new product lines or extensions can all be good reasons to rebrand with a name that’s more comprehensive. In an unusual move in 2002, First Union bank bought Wachovia and changed its name to… Wachovia. This helped it escape some baggage the First Union brand had built up over some years. Of course, less than 10 years later Wachovia was swallowed up by Wells Fargo.

The purpose of a re-brand is typically to signal a big change, but since the switch to X, the company formerly known as… well, you know…is essentially going backwards as a brand. Ad sales are way down, staff has been dramatically cut, and restraints on hate speech have been eased. Changing the brand name to X seems to have been superfluous to any real positive movement for the company. Will it survive? Most likely, but for the brand formerly known as Twitter, X marks the spot of what it once was, not what it might aspire to be.