Should the city allow the Blue Bell-based tech company to place its name in 11-foot-high letters on the east and west sides of the stockier half of Liberty Place, we can all expect to have our skyline views irrevocably altered. Only we won't get to retreat to the penthouse on the 58th floor to sulk about it.

Not that there's anything wrong with a company wanting its name in lights. Signs, as New York learned from Times Square, can be an energy drink for cities. After all, the whole point of putting up a soaring, swaggering skyscraper is so its owners and occupants (and designers) can shout, "Look at me."

The best towers, I'd argue, don't need signs in the sky; the design is the sign. But when companies insist, it's not unreasonable to expect them to earn their bragging rights.

Philadelphia has traditionally allowed "major tenants" to advertise their presence with big signs on their building facades. Usually, they're expected to place those signs just above the first level. But if you look skyward, you'll see more corporate logos than you might expect in our self-effacing, taste-conscious town - from the historic, sans-serif graphic masterpiece of PSFS to the brand new, acid-green ExcelleRx logo that crowns the 20-story Three Parkway building.

Unisys, however, is leasing a mere 31/2 floors at Two Liberty, or 7 percent of the building. It calls these offices its "global corporate headquarters," although it expects to send only 225 of its 1,700 Blue Bell employees to Center City. The token presence means the Fortune 500 company won't pay a whole lot in business taxes, while it's the employees who will bear the extra wage-tax burden. Sounds like Unisys got a great deal on a billboard.

Those details didn't stop the Nutter administration from endorsing the Unisys scheme without a Planning Commission review. Now - just like in the old John Street days - it's up to the Zoning Board of Adjustment to determine whether to grant a variance for the 60-foot-wide sign, which would be visible from Philadelphia International Airport to the Ben Franklin Bridge. The case could lower the bar for companies seeking high-rise, high-visibility advertisements for themselves.

Once it's OK for any company that leases a few random offices to scribble its name in the sky, every tall building in Philadelphia will be seen as a blank canvas. There are currently no written standards governing who gets skyline billing or what the signs should look like. The Art Commission, which rubber-stamped the Unisys application and is supposed to be the gatekeeper for such things, hasn't shown much rigor in evaluating these designs.

I don't believe Unisys' LED sign is quite as clunky as some opponents have argued (or that Two Liberty is quite as svelte as its architect, Scott Pratt of Murphy Jahn, claimed at last week's zoning hearing). But what if Cigna, which maintains a real corporate headquarters on 18 floors of Two Liberty, demands equal time?

Or the Residences at Two Liberty, which trumps them both with 20 floors? It could get ugly up there.

If any firm deserves to plaster its name across a Philadelphia skyscraper, it's Cigna, a company that has maintained a headquarters here since George Washington was president.

In fact, both Cigna and the residents believe Unisys pulled a fast one when it persuaded the building's owners to include the high-rise sign in its 15-year lease.

Those tenants have sued in federal court to block Unisys from sticking its big moniker across Two Liberty's 38th and 39th floors, which contain the building's ventilation system. That means a federal judge will ultimately determine the fate of the city's skyline. The zoning board hearing, which resumes Tuesday, is just a dress rehearsal.

Unisys' sign may have generated the most noise, but it would hardly be the most intrusive. In February, Wachovia received permission to wrap the delicate bell tower of the old PNB building just south of City Hall - home to a majestic peregrine falcon - with its signature blue-and-green wave logo.

Though the letters would be a reasonable 10 feet high, they would be set against a lighted, 39-foot-tall, multicolored wave wrap. In comparison, the PSFS letters are a modest 27 feet. At least, Wachovia leases nine floors in the 28-story tower, along with space in other buildings, and employs a hefty 4,000-strong workforce in Philadelphia. Interestingly, the bank hasn't made a final decision on installation.

The real trouble with the Unisys sign is the ambiguous message it sends about Philadelphia. The company has cleverly played into local insecurities by suggesting that a refusal is evidence the city isn't a business-friendly place, and has vowed to break its lease unless the sign is approved. But others will read different meanings into that sign.

Like Philadelphia sells itself cheap. Or bullies get their way.

Tax reformer Brett Mandel, of Philadelphia Forward, argues that special deals "create resentment and anger among those firms we have to retain." Imagine what went through the minds of Cigna execs when they learned they would be occupying the Unisys building. The best way to prove the city is a good home for corporations, he says, is to make sure the rules are transparent, equitable and affordable for all.

Given that the public is increasingly numb to traditional advertising - who looks at Web pop-ups? - Philadelphia is likely to see more requests for signs in offbeat locations. Companies want our eyeballs, and our architecture may be the last thing we can't avoid looking at.

The city can handle, and even benefit from, the energy of interesting, well-designed and carefully placed signs. But only if they stand for something.