On: Airlines are running out of 4-digit flight numbers

[philjohn]

I still love the bit of book trivia that since 13 digit EAN's start with a country code, you can convert an ISBN-10 into an ISBN-13 by prepending it with the code for "book land" - 978.

(I worked on Library Management Software for 6 years).

[bloak → philjohn]

You also have to recompute the check digit, of course, for example: 0131103628 -> 9780131103627

[philjohn → bloak]

Ah yes, you're indeed correct - I forgot that :D

I also used to know what most of the MARC 21 (library interchange format) codes stood for ... but that has now been purged from the memory banks ... except 245 $c - statement of responsibility https://www.loc.gov/marc/bibliographic/bd245.html