There have been a few discussions in the Apache Forum about this topic, but because it depends on the server setup, the configuration of the server I believe it is best to consult with the host for a definitive answer. If you like, you can try and test some of the suggested methods. Remember that the "ExpiresActive ON" and "Expires Default" set the basics and additional controls for files that change more frequently or files you do not want cached are what you should work on.

The formats are explained at the Apache site: [httpd.apache.org...] and you can see a few past discussions in the Apache Forums here: [webmasterworld.com...] and also here: [webmasterworld.com...] that may help. Because the "best" way to do this depends on the type of files, whether they are static or dynamically generated and on the server's settings, there are a lot of variables. Best practice is to read and try, by using tools to check the headers, clearing your cache and testing.

Setting Expires headers for dynamically generated files (such as Drupal or WordPress generates) is best done internally - within the CMS rather than in .htaccess because the "files" don't exist until they are requested.

many thanks for the links not2easy

Just. FYI - even if you do install correct caching and it is working as intended, Page Speed may not recognize it and may return the same "Leverage browser caching" warning so it's best to validate at another tool (or more.)

Also, if using HTTPS, Page Speed results may also report caching warning depending on the header your server returns.

Indeed, other page tests confirm valid browser caching andi have tried various methods, but none does not please page speed ... so i am still searching for a functioning entry.

Perhaps someone may have a functioning htaccess entry?

Don't worry about it. Not passing all the rules at Page Speed means nothing in terms of your page ranking. The tool is buggy.