Si es correcto
También podes usar headers (usas o uno u otro no los dos métoods)
Código Apache:
Ver original#### Cache
# anual
<FilesMatch "\.(ico|gif|jpg|jpeg|png|flv|pdf|woff|eot|svg|ttf|flv|swf)$">
Header set Cache-Control "public, max-age=29030400"
</FilesMatch>
# semanal
<FilesMatch "\.(js|css|htc)$">
Header set Cache-Control "max-age=604800"
</FilesMatch>
# 3 horas
<FilesMatch "\.(php|html|htm|txt|html5|phtml)$">
Header set Cache-Control "max-age=10800"
</FilesMatch>
# no cachear
<FilesMatch "\.(pl|cgi|spl)$">
Header unset Cache-Control
Header unset Expires
Header unset Last-Modified
FileETag None
Header unset Pragma
</FilesMatch>
los valores de max-age son en segundos
SAludos