What are the windows requirements for an OpenType font to be installable?

As someone on the Typophile forum pointed out, it turns out the "name" table is incomplete as far as Windows is concerned. While the Microsoft Font Validator does not flag any issues with it, the font must list the following name table entries for it to be installable:

1: the regular font name
2: the font subfamily ("Regular", etc)
3: any (seriously, ANY) string to act as a unique font identifier
6: the postscript font name (a subset of true ASCII. Not ANSI)

The font as I had defined it was using NameIDs 1, 2, 4 and 5; while 4 and 5 are in fact required for "validation", they turn out to be utterly irrelevant for preview/installation, whereas 3 and 6 are critical. Who knew (seriously, who knew... if you did, I want to talk to you in chat or on twitter or something to pick your brain =)

(note that 4 and 5 are still required to make the font installable on OSX)

2017 edit: Microsoft's Font Validator was open sourced in 2015, and as MS was (for legal reasons) unable to merge in significant community contributions, a community-maintained fork was set up instead, and is being kept in sync with the changes in the OpenType spec over on https://github.com/HinTak/Font-Validator -- If Font Validator is part of your toolset, you absolutely want to start using this fork instead.