Irond Ltd. (Russian: ООО "Айронд") is one of the largest labels in Russia, specializing in heavy / metal and other alternative music. Most of released material are licensed re-releases of official CDs/DVDs from western bands. Several Russian bands / musicians are subscribed to Irond Ltd. directly and get their music published there.
All Irond Ltd. catalog numbers are formed using a simple scheme:
IROND FF YY-NNNN
Where FF is release format, YY are last 2 digits of a release year, NNNN is a release number. Releases are numbered sequentially from the very first ones back in 2000, increasing by 1 for every release.
All their releases can be found on their website, and they include information such as catalog number, licensing, etc.