What’s so special about ABC’s “Home Improvement,””Grace Under Fire,””20/20, “”PrimeTime Live,””Day One” and NBC’s “Now”?

During the second week of the Olympics, each of those programs were labeled as “specials,” meaning those telecasts don’t count in their respective season-to-date Nielsen ratings.

In a conference call with reporters, CBS senior VP of research David Poltrack accused ABC of using the ploy so that “Home Improvement’s” ratings weren’t “dragged down,” thereby endangering its chances of finishing the season as the nation’s top-rated program. “Improvement” is neck-and-neck with “60 Minutes” for the top slot, with the CBS show ahead by 0.1 of a rating point.

“‘Day One’ is certainly not going to beat out ’60 Minutes,’ and we did it with that, as well,” ABC exec VP of research Peter Chrisanthopoulos fired back. “We were dealing with one of the most atypical weeks in TV. The week is considered an anomaly and we shouldn’t be benefiting or penalizing (regular) shows.”

Rivals also point out that CBS employed the same labeling tactics with “60 Minutes,” tagging the edition that aired opposite NBC’s Jan. 30 Super Bowl telecast as a special.

“David (Poltrack) can’t have it both ways. He ought not to exercise the prerogative and complain about it at the same time,” said Nicholas Schiavone, NBC’s VP of media & marketing research.

The option to code a program as a special, when its content and competition are both deemed atypical, is frequently employed by local television stations afraid of having their fare slaughtered in the ratings by major events. Networks usually use the Nielsen loophole less often.

Follow @Variety on Twitter for breaking news, reviews and more