Understanding IOS 6500

[mdrangell22]

Hello guys 

I have read this document but I don't understand it completely:

https://www.cisco.com/c/en/us/products/collateral/switches/catalyst-6500-series-switches/prod_bulletin0900aecd804f0694.html

I need to know what exactly does all the numbers and letters that make an IOS for Switch 6500

Example for the IOS 

15.1.2-SY12 (MD)

If I follow what it says in the link above I suppose this would be

15.1 and SY= Major Release Identifier

.2= Release Maintenance Identifier

12= Rebuild Identifier

Now what exactly does all of these names?

In the document it says that in New Technology Identifier is when  bugs are fixed, but here I don't see new techonology identifier so the bug fixes are made in rebuild identifier?

[Reza Sharifi]

Most releases have bug fix in them with some also adding new software and/or hardware feature.

Have a look at this link for all sub-releases for 15-1SY bug fixes, new features, etc... 

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst6500/ios/15-1SY/release_notes.html

HTH