g1smd - 6:55 pm on Oct 16, 2012 (gmt 0)

The parameter URL to extensionless URL external redirect should test THE_REQUEST in a preceding RewriteCond. This ensures that only external requests with parameters are redirected, not those as a result of a previous internal rewrite.

The parameter to extensionless external redirect should be listed before the extensionless to parameter internal rewrite.

Escape literal periods in the external redirect RegEx pattern.

Do NOT use the NC flag in the internal rewrite ruleset otherwise you'll have a major Duplicate Content problem. Use all lower case for extensionless URLs.