'code' and 'tt' can be used for inline code posting, whereas 'pre' can be used for block code posting.
Text inside 'pre', 'code', 'kbd', 'style', 'script', 'tt' is not touched by WordPress for transformation. I have checked this in version 2.8 and newer.
0.5
Development release
Requires: 2.0.2 or higher Compatible up to: 3.1.4 Last Updated: 2010-9-8 Downloads: 694