- Avoid "unrevertable" changes if you can: * Don't submit (commit) code that can't be easily reverted - e.g. don't introduce code that if ran dozen or more ti

- Avoid "unrevertable" changes if you can: * Don't submit (commit) code that can't be easily reverted - e.g. don't introduce code that if ran dozen or more times on production systems, then reverting it would require other files to be reverted/recreated/rewritten from scratch apart from itself. (Someone decides to go from XML->JSON, or JSON->XML, or one scripting language to another - that is a very drastic change, because people would've picked on the new system, and few weeks later if it turns out it's not working, not only you have to go back to the original state, you have to rewrite whatever was changed into the scripting/etc. files back into the old one - and sometimes that's not straightforward).