The specifications for the compact disc and compact disc players developed by Sony, Philips, and Polygram.

A summary of this standard:

the Disc
Playing time: 74 minutes, 33 seconds maximum
Rotation: Counter-clockwise when viewed from readout surface
Rotational speed: 1.2 - 1.4 m/s. (constant linear velocity)
Track pitch: 1.6 µm
Diameter: 120 mm
Thickness: 1.2 mm
Center hole diameter: 15 mm
Recording area: 46 mm - 117 mm
Signal area: 50 mm - 116 mm
Material: Any acceptable medium with a refraction index of 1.55
Minimum pit length: 0.833 µm (1.2 m/s) to 0.972 µm (1.4 m/s)
Maximum pit length: 3.05 µm (1.2 m/s) to 3.56 µm (1.4 m/s)
Pit depth: ~0.11 µm
Pit width: ~0.5 µm

the Optical System
Standard wavelength: 780 nm (7,800 Å)
Focal depth: ± 2 µm

the Signal Format
Number of channels: 2 channels (4 channel recording possible)
Quantization: 16-bit linear
Quantizing timing: Concurrent for all channels
Sampling frequency: 44.1 kHz
Channel bit rate: 4.3218 Mb/s
Data bit rate: 2.0338 Mb/s
Data-to-channel bit ratio: 8:17
Error correction code: Cross Interleave Reed-Solomon Code (with 25% redundancy)
Modulation system: Eight-to-fourteen Modulation (EFM)

Colloquially, in video games, background music that is streamed off the CD, and is stored on the disc as CDDA (red book) tracks.

IUCN Red Data Book of Endangered Species

I remember growing up and reading the names of all the disappearing animals in the world in elementary school. It was a big red hardcovered book. I wondered if all those species twenty later were dead now and if there was a new 'red book'.

I know where all the species are kept now duely noted as they wink out. A new book of the dead and almost dead. It's also now a well mantained website database kept at

For reference here are the original IUCN threat categories.

  • It was later revised and updated for the IUCN red list in 1994 with modified catagories with better criteria to determine the placement of the different taxa
  • These catagories only apply to taxa in the wild

  • Extinct (Ex)

    Taxa not definitely located in the wild during the past 50 years (criterion as used by the Convention on International Trade in Endangered Species of Wild Fauna and Flora).

    Extinct/ Endangered (Ex/E)

    Taxa that are suspected of having recently become extinct.

    Endangered (E)

    Taxa in danger of extinction and whose survival is unlikely if the causal factors continue operating. Included are taxa whose numbers have been reduced to a critical level or whose habitats have been so drastically reduced that they are deemed to be in immediate danger of extinction. Also included are taxa that may be extinct but have definitely been seen in the wild in the past 50 years.

    Vulnerable (V)

    Taxa believed likely to move into the 'Endangered' category in the near future if the causal factors continue operating. Included are taxa of which most or all the populations are decreasing because of over-exploitation, extensive destruction of habitat or other environmental disturbance; taxa with populations that have been seriously depleted and whose ultimate security has not yet been assured; and taxa with populations that are still abundant but are under threat from severe adverse factors throughout their range.

    Rare (R)

    Taxa with small world populations that are not at present 'Endangered' or 'Vulnerable', but are at risk. These taxa are usually localized within restricted geographical areas or habitats or are thinly scattered over a more extensive range

    Indeterminate (I)

    Taxa that are known to be 'Endangered', 'Vulnerable' or 'Rare' but where there is not enough information to say which of the three categories is appropriate.

    Even of they are no longer the offical terms they are still the terms most people use in conversation without resorting to more specialised conservation jargon.

    recursive acronym = R = red wire

    Red Book n.

    1. Informal name for one of the four standard references on PostScript ("PostScript Language Reference Manual", Adobe Systems (Addison-Wesley, 1985; QA76.73.P67P67; ISBN 0-201-10174-2, or the 1990 second edition ISBN 0-201-18127-4); the others are known as the Green Book, the Blue Book, and the White Book (sense 2). 2. Informal name for one of the 3 standard references on Smalltalk ("Smalltalk-80: The Interactive Programming Environment" by Adele Goldberg (Addison-Wesley, 1984; QA76.8.S635G638; ISBN 0-201-11372-4); this too is associated with blue and green books). 3. Any of the 1984 standards issued by the CCITT eighth plenary assembly. These include, among other things, the X.400 email spec and the Group 1 through 4 fax standards. 4. The new version of the Green Book (sense 4) -- IEEE 1003.1-1990, a.k.a ISO 9945-1 -- is (because of the color and the fact that it is printed on A4 paper) known in the USA as "the Ugly Red Book That Won't Fit On The Shelf" and in Europe as "the Ugly Red Book That's A Sensible Size". 5. The NSA "Trusted Network Interpretation" companion to the Orange Book. 6. Nemeth, Snyder, Seebass, Hein; "Unix System Administration Handbook, Second Edition" (Prentice Hall PTR, New Jersey; 1995; QA76.76.063N45; ISBN 0-13-151051-7). See also book titles.

    --The Jargon File version 4.3.1, ed. ESR, this entry manually entered by rootbeer277.

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