ITU-RT-H-SMTP-Rec. What?

To quote an old, old line, the best thing about standards is that there are so many of them. High definition TV is no exception. The simple (?) acronym HD-SDI is actually a catch-all for a confusing brace of standards. Here, for my convenience, several are itemised (along with some that aren't HD in the firmly old-school, 1940s sense.) First, SMPTE:

SMPTE 170M

NTSC (Analog composite)

SMPTE 240M / 260M

1125i

SMPTE 274M

1080i & 1080p

SMPTE 296M

720p

SMPTE 259M

SD-SDI (ie. the serial interface itself)

SMPTE 292M

HD-SDI (likewise)

SMPTE 372M

Dual-link HD-SDI

SMPTE 272M

SDI Embedded audio

SMPTE 299M

HD Embedded audio

And then ITU (previously EBU, previously various others...):

ITU-R BT Rec 601

SD PAL digital coding

ITU-R BT Rec 709

Erm...

So, that's neither exhaustive nor correct. I'll update it one day. Perhaps.