This Message appeared on 02.07.2007 on most popular SEO forum in Russia Forum.Searchengines.Ru (http://forum.searchengines.ru/showthread.php?t=149644)

Translation:
"Dear web-masters!

"Tonight search algorithm on one of Yandex data-centers was renewed. For couple days different users will get different results for same keywords. When we'll put new algorithms on all our servers this difference will disappear.

"We hope to improve relativity for number of keywords. So if you spot something became worser - contact us on http://feedback.yandex.ru/?from=webmaster explainig which pages are missing from SERP.

"To know which algorithm you are using go on http://www.yandex.ru/cgi-bin/hostname - there you can see server name. If it looks like front??.yandex.ru or ludi.yandex.ru than you're dealing with new algorithm if it's like sfront2-???.yandex.ru try next time!

"Thank you, and we hope our changes will be pleasant for you and our customers.

"Sincerely yours,
"Alexander Sadovsky"


This post had caused more than 1000 replies in less than 9 days and still it's one of most discussed topics.