It may come as a surprise to many, but even as 3D and 4K TV looms and HDTV is in danger of becoming passe, some “HD” cable channels are fudging the term “high-definition.”

Many channels show standard-def library content, and most label programs accordingly in onscreen program guides, appending an “HD” tag only to shows shot and mastered in true HD. But a few, most notably Turner Classic Movies, present themselves as “HD” even though most of their programming might better be called “faux-HD.” And some bizzers are irked by the practice.

“If a station advertises (it is) HD and (it is) not, that is false advertising,” says Raymond Blumenthal, VP of broadcast systems at Tiffen, and Panasonic’s former point-man for the introduction of HDTV broadcasting in New York, as well as for ABC and HBO’s conversion to HDTV.

Networks are able fudge the term HD because it covers a range of resolutions and formats. Full HD is 1080 lines of resolution, all of them refreshed at least 30 times a second, aka 1080p. This is the resolution of Blu-ray disks and some streaming services. No cable or broadcast networks have enough bandwidth for full HD, so broadcast HDTV is either 720p or 1080i.

Many networks put an HD tag on the program guide for shows that were shot and mastered at one of those standards. But there’s another way to present a form of HD: Take a standard-def master, “up-res” it to add more pixels (as some DVD and Blu-ray players do) and send it out as “HD” programming.

NBC-Universal presents “Cheers” up-res’d from standard-def masters, and NatGeo sometimes will up-res archival footage.

Turner Classic Movies, though, has quietly made up-resing the rule, not the exception. TCM has a TCM HD channel, but its program guide listings lack HD tags. In fact, only 25% of movies shown on TCM HD have been scanned and mastered in HD. The rest are up-res’d, delivering a picture markedly inferior to a true HD master.

“In 1999, HBO was 45% true HD,” says Bob Zitter, HBO’s exec VP of technology and chief technical officer, “but we wouldn’t label anything HD if it was not native HD. I got into debates with some colleagues over networks that labeled everything HD. I felt that was wrong and would come back to bite them.”

While none of these nets yet sport bloody toothmarks, there is pushback against the practice, especially against TCM HD, on blogs and websites catering to movie buffs and video cognoscenti.

The nets that send out up-res’d standard-def and call it HD seem to have a mantra: Even the worst HD is better than SD. TCM, in particular, says its up-res’d movies are better than the standard-def alternative.

“We have reasonable explanations for where we’re at today,” says TCM general manager Jeff Gregor. “(100% HD) will come. We’re happy to move there when it makes sense from a product standpoint and a business standpoint.”

Ostensibly, it takes time and money to convert to HD masters. Gregor says TCM has the technology and the capability, but adds that the network is not entirely responsible for converting old films, since its library isn’t fully owned and it works with all the studios to license these films.

“We have to work with the master that exists until (it’s) eventually upgraded to HD status,” Gregor says.

The puzzle is in the labeling. Some HD channels, like those of Showtime and MTV, display a small “HD” in the top right corner of the title when airing true HD shows. Some HD nets, such as VH1 HD and IONE HD have less than half their programs labeled HD in a given 24-hour period, but they clearly label which shows are HD, and which aren’t.

TNT HD has been criticized for presenting some programing in what’s been dubbed “Stretch-o-Vision” (a soft, 4×3-stretched-to-16×9, up-converted picture). The network, which wouldn’t respond to repeated inquiries, says on the HD section of its website: “Take one look at HDTV and the difference in quality between HD and standard definition TV is crystal clear. Standard definition broadcast television (NTSC) picture is constructed of 486 visible picture lines. An HDTV broadcast has up to 1080 lines, resulting in six times the picture clarity vs. standard definition.”

Repercussions for TCM and TNT have been few. But those nets are in competition with Blu-ray discs and true HD streaming services, so they benefit from misleading consumers who might otherwise go elsewhere to watch the best possible transfer of classic movies — or even classic sitcoms.

Any way you look at it, the picture they’re leaving is fuzzy at best.