IBM general counsel Robert Weber isn’t afraid to take on a fight. Outside investment in law firms? He told The Wall Street Journal he opposes it. Should the general counsel be the conscience of the company? No, he explained to our sibling publication corpcounsel.com, that’s not the right mind-set. On a frigid February day, I drove up to the computer giant’s woodsy Westchester, New York, campus to talk to the former Jones Day trial lawyer about another no-holds-barred topic: his pet peeves about his outside counsel.

It all starts with "The List." Every law department has one, whether it’s a formal document or something the GC keeps in his head: a rundown of firms that the law department will not hire. There are approximately 10 firms (including one from the Magic Circle) that are currently persona non grata to Weber’s 500 in-house lawyers. (IBM’s roster includes some 10 individual lawyers on its blacklist, too.)

How do you get on this lineup? The first sin is pretty simple. Forget what all those business development gurus say. Don’t solicit Weber’s corporate counterparts for business. Never. Ever. It’s fine for lawyers to socialize with the executives. But Weber and his crew don’t want you squeezing the MBAs for legal work. It puts the in-house team in an awkward position, and Weber wants the company’s legal work centralized through the law department.

Firms also land on the company’s ignominious list for bad citizenship. If you’re insensitive to the ethics of the profession, that’s a problem. If you ask IBM to waive a conflict and the company says no, and you whine about it—bye. Other transgressions simply irritate Weber. He asked one of the firm’s outside litigators why the attorney hadn’t sought a jury trial in a particular case. Simple question, right? Weber did not appreciate the four-page memo that he received in return. The memo-writer "hadn’t spent a minute trying to understand his client," says Weber.

The GC also disdains cold pitch letters. Many firms follow big companies’ dockets. When the corporation is sued, the firm churns out a form letter and emails it with a copy of the complaint offering assistance. Brilliant marketing? Hardly. When IBM legal receives these missives, the law department sends a reply asking the lawyer to list the cases she’s tried in the venue where IBM was sued. IBM doesn’t typically get a lot of responses back.

Weber had plenty of good things to say about IBM’s big firms, including Kirkland & Ellis; Cravath, Swaine & Moore; and Hogan Lovells. He also praised the employment-centered firms such as Littler Mendelson and Jackson Lewis and firms that are less well-known, such as Desmarais LLP and Houston’s Yetter Coleman. What does the GC like about them? Their lawyers give crisp, clear legal advice. He’ll take the business advice on the side, but he wants the straight legal analysis from these highly paid lawyers first. Weber also appreciates lawyers who recognize the all-consuming 24/7 nature of the work at IBM. Outside counsel who act as if the company’s in-house lawyers are "in a biosphere," he says, just don’t cut it.

These are the particular preferences of one GC—but your own clients may feel the same way. Talking to them about these issues might even keep you off The List.

This article originally appeared in The American Lawyer.