Context: Since the formal adoption of digital video broadcasting's (DVB) widescreen HDTV transmission modes in the early 2000s; the 525-line NTSC (and PAL-M) systems, as well as the European 625-line PAL and SECAM systems, are now regarded as standard definition television systems.

Question: When was widescreen HDTV transmission modes formally adopted?
Answer: early 2000s

Question: In addition to the 625-line PAL system, what European system is considered a standard definition television system?
Answer: SECAM systems

Question: In addition to the NTSC system, what 525-line system is considered a standard definition television system?
Answer: PAL-M

Question: 525 and 625-line systems are now considered what?
Answer: standard definition television systems

Question: What does DVD stand for?
Answer: Unanswerable

Question: When was widescreen SDTV transmission modes formally adopted?
Answer: Unanswerable

Question: In addition to the 625-line PAL system, what Asian system is considered a standard definition television system?
Answer: Unanswerable

Question: In addition to the NTSC system, what 525-line system is considered a high definition television system?
Answer: Unanswerable

Question:  525 and 625-line systems are not considered what?
Answer: Unanswerable