Technicolor DTMF sequences

Many SP-mode videotapes duplicated at Technicolor Videocassette beginning in mid 1989 and ending in mid 2003 included a sequence of DTMF phone-dial tones at the start and/or end of the tape. On certain tapes with this sequence, a faint sound of extra tones precedes it. It is not yet known exactly what each tone in the sequence indicates, except there's usually a pause between the first and second tones, the second tone is always 1, the third tone is always #, and the fourth tone is always D. This sequence was used to encode information on the master tape by providing information on settings such as format, running time, audio level balance, volume control, etc. to automatic videotape duplication machines. This allowed better replication of the master tapes that were copied onto the formats the videotapes were released in.

Oddities About This Sequence on Certain VHS Tapes

 * On certain pressings of CBS/Fox releases from 1989-1990, this sequence occurs during the still-framed 1983-1999 Fox FBI warning screen/1984-2000 CBS/Fox Video logo combo that likely occured at the start of those pressings due to some sort of processing error.
 * On some VHS tapes released by Buena Vista Home Entertainment, this sequence occurs during the company's FBI warning screens, most notably on couple pressings of certain Walt Disney "Black Diamond" Classics and Walt Disney "The Fancy Shield" Mini-Classics titles from this year and possibly 1992, like "The Reluctant Dragon" (1941), "Fantasia" (1940), "The Rescuers" (1977), and "The Rescuers: Down Under" (1990).
 * Usually, this sequence is heard in the left audio channel, but occasionally, it could be on the right (most notably on certain pressings of the 1993 VHS of Disney's "Pinocchio" (1943)). Funnily enough, some YouTube users falsely label this sequence as coming from the specific videotape player model, rather than the specific videotape itself, and find this sequence demonic, scary or both. In addition, they also assume that this sequence must have been a recording error, as it sounds like someone punching numbers on a 1980s telephone.
 * Another YouTube user with a blue-background profile theorizes that this sequence could have been used to see if the tape is working or malfunctioning. However, they also stated that they don't know much about VHS tapes meaning they could be wrong.