Will this .htaccess file do any good?

I found this on another website. There were minimal explanations for what it does and how.

Is this code legit??? Worth doing???

Code:

01<ifModule mod_expires.c>02  ExpiresActive  On
03  ExpiresDefault "access plus 1 seconds"
04  ExpiresByType  text/html "access plus 1 seconds"
05  ExpiresByType  image/gif "access plus 2592000 seconds"
06  ExpiresByType  image/jpeg "access plus 2592000  seconds"
07  ExpiresByType image/png "access plus 2592000 seconds"
08  ExpiresByType  text/css "access plus 604800 seconds"
09  ExpiresByType  text/javascript "access plus 216000  seconds"
10  ExpiresByType  application/x-javascript "access plus  216000 seconds"
11</ifModule>
12<ifModule mod_headers.c>
13  <filesMatch  "\\.(ico|pdf|flv|jpg|jpeg|png|gif|swf)$">
14    Header  set Cache-Control "max-age=259200,  public"
15  </filesMatch>
16  <filesMatch  "\\.(css)$">
17    Header set  Cache-Control "max-age=604800, public"
18  </filesMatch>
19  <filesMatch  "\\.(js)$">
20    Header set  Cache-Control "max-age=21600, private"
21  </filesMatch>
22  <filesMatch  "\\.(xml|txt)$">
23    Header set  Cache-Control "max-age=21600, public,  must-revalidate"
24  </filesMatch>
25  <filesMatch  "\\.(html|htm|php)$">
26    Header  set Cache-Control "max-age=1, private,  must-revalidate"
27  </filesMatch>
28</ifModule>
29<ifModule mod_headers.c>
30  Header  unset ETag
31</ifModule>
32FileETag None
33<ifModule mod_headers.c>
34  Header  unset Last-Modified
35</ifModule>

Thanks again peeps.

This is for mod_expires caching timeouts.

I've found it to be 50/50. On some servers, it works great. On others, you never see new threads until you do a hard refresh, even if you're only setting the cache for html pages to 1 second.

Of course, this only works if you have mod_expires compiled into your apache build.

Note, do NOT put the line numbers in the file (1-35).

I'm on lightspeed.