Again, the target list is strong on symbolism.

The World Bank. The International Monetary Fund. The New York Stock Exchange. Such names roll off the tongue in the fullness of their function, citadels of the international capitalism the al Qaeda terrorists love to hate.

And, again, the fact that the targets are located in the political and financial capitals of the United States -- with a possible side trip to Prudential Financial's headquarters in Newark -- also is of prime symbolic importance.

As the list of targets revealed Sunday by Homeland Security Secretary Tom Ridge demonstrates -- again -- when it comes to the grisly business of blowing up buildings, these media-savvy terrorists clearly prefer a certain kind of target: Big. Global. American.

We learned this after the deadly attacks of Sept. 11, 2001, on the World Trade Center towers in New York and the Pentagon on the Virginia side of the Potomac.

This time around, the difference that shouts itself, that is worth celebrating, is that this list is a warning rather than a tragic aftermath. Whether it ought to have been a public forewarning, with all the attendant hoopla, rather than a secret directed to the attention only of the intended targets is an open question.

Either way, advance notice (even without a date certain) reduces the probability of a successful attack on these buildings. Security officials and advisers for each of the institutions on the list can use the information to increase vigilance and fix what's ailing in their precautionary systems.

Yet, there are always other targets. Even if one limits the list to big buildings in the United States housing global institutions, it would be quite long. Sunday's list actually is a case in point.

It is hardly surprising that the terrorists would choose those two Washington institutions and the New York Stock Exchange as prominent targets. But the Prudential building in Newark? The Citigroup Center in midtown Manhattan?

These are, I am sure, immense companies of vast international importance. But in terms of star power, symbolic import or whatever you want to call it, they are average to the point of near-invisibility.

This is true even architecturally. The Newark building is one of an interchangeable breed that U.S. architectural offices habitually stamped out a few decades ago. It could be anywhere. And while the Citigroup building, designed by Hugh Stubbins in the early 1970s, possesses some architectural distinction -- the dramatically angled top and cantilevered bottom, especially -- its symbolism is strictly visual.

In fact, none of the buildings on this new list possesses the identifiable messages of the Trade Center towers or the Pentagon. For reasons only vaguely architectural, both of those edifices united symbolic meaning with physical form.

Because of their size and isolation on the skyline, the trade towers became worldwide symbols of an economic system. Because of its location and distinctive shape, the Pentagon became an instantly recognizable symbol of U.S. military might.

Arguably, the Roman facade of the New York Stock Exchange is familiar enough and has been around long enough to possess this kind of carry. But I doubt it. The trading floor is the more meaningful image, and on television screens it morphs into a generalized image of any trading floor anywhere.

The Washington buildings are little known outside of our fair city. Both are good buildings, in their way. The IMF building, designed by Vincent Kling & Partners in 1973 and added to by the same Philadelphia firm in 1983 and 1994, is a top-heavy but not inelegant precast concrete goliath. Its claim to local fame really is its hollow interior, which inaugurated downtown's age of atria three decades ago.

The World Bank Headquarters, designed by Kohn Pedersen Fox Associates in 1990 and completed in 1997, is a tour de force of organization enclosing an even bigger atrium. Its outstanding feature is the dynamic front elevation, facing Pennsylvania Avenue between 18th and 19th Streets NW, with that huge, tilted glass wall.

The underlying, anxious-making message of the new list is that there can be other target lists, and lists of lists. We, in response, compile our own lists. And as we see in the continuing fortification of Washington, saying no to requests for security does not come easily. The list of needs and demands -- not always synonymous terms -- always seems to be expanding.

It is thus advisable to approach this entire subject of urban security in a terrorist time with a certain cold caution. As city dwellers and city builders, we have a duty not to overreact.

Yesterday, as I walked along Pennsylvania Avenue outside the World Bank building, the meaning of that splendid glass wall, designed to signal openness, seemed sadly ironic.

As an institution the World Bank is renowned; its headquarters is not.The International Monetary Fund building is familiar to local residents, but virtually anonymous outside Washington.Prudential's headquarters in Newark, lacking any symbolic import.Security has tightened at the Citigroup Center in New York, another target on the al Qaeda list.