The InChI (International Chemical Identifier from IUPAC) has been blogged earlier here. RSC have especially taken this on board in their Project Prospect and now routinely syndicate InChI identifiers in their RSS feeds as blogged here.

As reported variously last month (see here for one such review) IUPAC have now released a new (1.02beta) version of their software which allows hashed versions (fixed length 25-character) of the InChI, so-called InChIKey's, to be generated which are much more search engine friendly. Compare a regular InChI identifier:

InChI=1/C49H70N14O11/c1-26(2)39(61-42(67)33(12-8-18-55
-49(52)53)57-41(66)32(50)23-38(51)65)45(70)58-34(20-29-1
4-16-31(64)17-15-29)43(68)62-40(27(3)4)46(71)59-35(22-30
-24-54-25-56-30)47(72)63-19-9-13-37(63)44(69)60-36(48(7
3)74)21-28-10-6-5-7-11-28/h5-7,10-11,14-17,24-27,32-3
7,39-40,64H,8-9,12-13,18-23,50H2,1-4H3,(H2,51,65)(H,54,56
)(H,57,66)(H,58,70)(H,59,71)(H,60,69)(H,61,67)(H,62,68)(H,73,74)
(H4,52,53,55)/f/h56-62,73H,51-53H2

with its InChIKey counterpart:

InChIKey=JYPVVOOBQVVUQV-UHFFFAOYAR

That's some saving.