Ottimizzazione .htaccess

Ciao ragazzi, pagespeed mi segnala questo problema (da ieri):

Nelle seguenti risorse manca una convalida della cache. Le risorse che non specificano una convalida della cache non possono essere aggiornate in modo efficiente. Specifica un'intestazione Last-Modified o ETag per abilitare la convalida della cache per le seguenti risorse:

I file segnalati sono quasi tutti .png

Vi incollo il mio .htaccess, mi dite se secondo voi è ok o se bisogna apportare delle modifiche? Grazie!

RewriteEngine on


# This file is only needed if you have set the Forum Component URL in your admincp and you are
# using the mod_rewrite option for friendly urls. If this is the case, copy this file
# to your forum component stub directory.


# If you are having problems or are using VirtualDocumentRoot, uncomment this line and set it to your forum component directory.
# RewriteBase /forum-stub-directory/


# If you are having problems with the rewrite from content/ to , uncomment this line to turn MultiViews off.
# Options -MultiViews


RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d


RewriteRule ^.*$ - [NC,L]


# Forum
RewriteRule ^threads/.* showthread.php [QSA]
RewriteRule ^forums/.* forumdisplay.php [QSA]
RewriteRule ^members/.* member.php [QSA]


RewriteEngine On
RewriteRule ((urllist|sitemap).*\.(xml|txt)(\.gz)?)$ vbseo_sitemap/vbseo_getsitemap.php?sitemap=$1 [L]




# aggiunta inizio
# BEGIN Browser Caching/Headers
<IfModule mod_mime.c>
AddType text/css .css
AddType application/x-javascript .js
AddType text/richtext .rtf .rtx
AddType image/svg+xml .svg .svgz
AddType text/plain .txt
AddType text/xsd .xsd
AddType text/xsl .xsl
AddType video/asf .asf .asx .wax .wmv .wmx
AddType video/avi .avi
AddType image/bmp .bmp
AddType application/java .class
AddType video/divx .divx
AddType application/msword .doc .docx
AddType application/x-msdownload .exe
AddType image/gif .gif
AddType application/x-gzip .gz .gzip
AddType image/x-icon .ico
AddType image/jpeg .jpg .jpeg .jpe
AddType application/vnd.ms-access .mdb
AddType audio/midi .mid .midi
AddType video/quicktime .mov .qt
AddType audio/mpeg .mp3 .m4a
AddType video/mp4 .mp4 .m4v
AddType video/mpeg .mpeg .mpg .mpe
AddType application/vnd.ms-project .mpp
AddType application/vnd.oasis.opendocument.database .odb
AddType application/vnd.oasis.opendocument.chart .odc
AddType application/vnd.oasis.opendocument.formula .odf
AddType application/vnd.oasis.opendocument.graphics .odg
AddType application/vnd.oasis.opendocument.presentation .odp
AddType application/vnd.oasis.opendocument.spreadsheet .ods
AddType application/vnd.oasis.opendocument.text .odt
AddType audio/ogg .ogg
AddType application/pdf .pdf
AddType image/png .png
AddType application/vnd.ms-powerpoint .pot .pps .ppt .pptx
AddType audio/x-realaudio .ra .ram
AddType application/x-shockwave-flash .swf
AddType application/x-tar .tar
AddType image/tiff .tif .tiff
AddType audio/wav .wav
AddType audio/wma .wma
AddType application/vnd.ms-write .wri
AddType application/vnd.ms-excel .xla .xls .xlsx .xlt .xlw
AddType application/zip .zip
</IfModule>
<IfModule mod_expires.c>
ExpiresActive On
ExpiresByType text/css A31536000
ExpiresByType application/x-javascript A31536000
ExpiresByType text/richtext A3600
ExpiresByType image/svg+xml A3600
ExpiresByType text/plain A3600
ExpiresByType text/xsd A3600
ExpiresByType text/xsl A3600
ExpiresByType video/asf A31536000
ExpiresByType video/avi A31536000
ExpiresByType image/bmp A31536000
ExpiresByType application/java A31536000
ExpiresByType video/divx A31536000
ExpiresByType application/msword A31536000
ExpiresByType application/x-msdownload A31536000
ExpiresByType image/gif A31536000
ExpiresByType application/x-gzip A31536000
ExpiresByType image/x-icon A31536000
ExpiresByType image/jpeg A31536000
ExpiresByType application/vnd.ms-access A31536000
ExpiresByType audio/midi A31536000
ExpiresByType video/quicktime A31536000
ExpiresByType audio/mpeg A31536000
ExpiresByType video/mp4 A31536000
ExpiresByType video/mpeg A31536000
ExpiresByType application/vnd.ms-project A31536000
ExpiresByType application/vnd.oasis.opendocument.database A31536000
ExpiresByType application/vnd.oasis.opendocument.chart A31536000
ExpiresByType application/vnd.oasis.opendocument.formula A31536000
ExpiresByType application/vnd.oasis.opendocument.graphics A31536000
ExpiresByType application/vnd.oasis.opendocument.presentation A31536000
ExpiresByType application/vnd.oasis.opendocument.spreadsheet A31536000
ExpiresByType application/vnd.oasis.opendocument.text A31536000
ExpiresByType audio/ogg A31536000
ExpiresByType application/pdf A31536000
ExpiresByType image/png A31536000
ExpiresByType application/vnd.ms-powerpoint A31536000
ExpiresByType audio/x-realaudio A31536000
ExpiresByType application/x-shockwave-flash A31536000
ExpiresByType application/x-tar A31536000
ExpiresByType image/tiff A31536000
ExpiresByType audio/wav A31536000
ExpiresByType audio/wma A31536000
ExpiresByType application/vnd.ms-write A31536000
ExpiresByType application/vnd.ms-excel A31536000
ExpiresByType application/zip A31536000
</IfModule>
<IfModule mod_deflate.c>
<IfModule mod_setenvif.c>
BrowserMatch ^Mozilla/4 gzip-only-text/html
BrowserMatch ^Mozilla/4.0[678] no-gzip
BrowserMatch bMSIE !no-gzip !gzip-only-text/html
BrowserMatch bMSI[E] !no-gzip !gzip-only-text/html
</IfModule>
<IfModule mod_headers.c>
Header append Vary User-Agent env=!dont-vary
</IfModule>
<IfModule mod_filter.c>
AddOutputFilterByType DEFLATE text/css application/x-javascript text/html text/richtext image/svg+xml text/plain text/xsd text/xsl text/xml image/x-icon
</IfModule>
</IfModule>
<FilesMatch "\.(css|js|CSS|JS)$">
<IfModule mod_headers.c>
Header set Pragma "public"
Header append Cache-Control "public, must-revalidate, proxy-revalidate"
</IfModule>
FileETag MTime Size
<IfModule mod_headers.c>
Header set X-Powered-By "Step by Step guide to speed up your VB4 (forum only)"
</IfModule>
</FilesMatch>
<FilesMatch "\.(rtf|rtx|svg|svgz|txt|xsd|xsl|RTF|RTX|SVG|SVGZ| TXT|XSD|XSL|)$">
<IfModule mod_headers.c>
Header set Pragma "public"
Header append Cache-Control "public, must-revalidate, proxy-revalidate"
</IfModule>
FileETag MTime Size
<IfModule mod_headers.c>
Header set X-Powered-By "Step by Step guide to speed up your VB4 (forum only)"
</IfModule>
</FilesMatch>
<FilesMatch "\.(asf|asx|wax|wmv|wmx|avi|bmp|class|divx|doc|doc x|exe|gif|gz|gzip|ico|jpg|jpeg|jpe|mdb|mid|midi|mo v|qt|mp3|m4a|mp4|m4v|mpeg|mpg|mpe|mpp|odb|odc|odf| odg|odp|ods|odt|ogg|pdf|png|pot|pps|ppt|pptx|ra|ra m|swf|tar|tif|tiff|wav|wma|wri|xla|xls|xlsx|xlt|xl w|zip|ASF|ASX|WAX|WMV|WMX|AVI|BMP|CLASS|DIVX|DOC|D OCX|EXE|GIF|GZ|GZIP|ICO|JPG|JPEG|JPE|MDB|MID|MIDI| MOV|QT|MP3|M4A|MP4|M4V|MPEG|MPG|MPE|MPP|ODB|ODC|OD F|ODG|ODP|ODS|ODT|OGG|PDF|PNG|POT|PPS|PPT|PPTX|RA| RAM|SWF|TAR|TIF|TIFF|WAV|WMA|WRI|XLA|XLS|XLSX|XLT| XLW|ZIP)$">
<IfModule mod_headers.c>
Header set Pragma "public"
Header append Cache-Control "public, must-revalidate, proxy-revalidate"
</IfModule>
FileETag MTime Size
<IfModule mod_headers.c>
Header set X-Powered-By "Step by Step guide to speed up your VB4 (forum only)"
</IfModule>
</FilesMatch>
# End Browser Caching/Headers


# aggiunta fine




#Compression
<IfModule mod_headers.c>
<IfModule mod_deflate.c>
AddOutputFilterByType DEFLATE text/css text/xml text/javascript application/x-javascript application/javascript
BrowserMatch ^Mozilla/4 gzip-only-text/html
BrowserMatch ^Mozilla/4\.0[678] no-gzip
BrowserMatch \bMSIE !no-gzip !gzip-only-text/html
</IfModule>
</IfModule>

Questo avviso ti viene fuori quando?

Su pagespeed! Prima era in medium priority, ora in low!

Altre due cosine, se non disturbo!

1) Come posso fare per combinare le immagini in sprite css? Il codice che ho inserito alla fine del file .htaccess è corretto? Sono su server dedicato managed, devo far abilitare qualcosa? In opzioni Cookie e Header, abilito o disabilito la compressione gzip delle pagine html?

2) Gmetrix mi segnala che ci sono tantissimo CSS inutilizzati (oltre il 50%). Come si fa a disabilitarli? è una cosa rischiosa?

Ah, per chiudere: keep alive me lo deve attivare chi gestisce il server, vero?

Grazie! :)