Yslow2 beacon parameters list

• w– size of the page in bytes (v1 sent size in kilobytes)
• o– overall YSlow grade calculated for the profile used
• u– URL of the page tested
• r– total amount of requests with empty cache
• s– page identifier for yahoo pages (like yahoo music, sports, etc), blank on non-yahoo pages
• i– testing profile used:
  • ydefault– YSlow (V2)
  • yslow1– Classic (V1)
  • yblog– Small Site or Blog
  • or custom profile’s title with dash-encoded spaces
• ynumreq–Make fewer HTTP requests
• ycdn–Use a Content Delivery Network (CDN)
• yexpires–Add Expires headers
• ycompress–Compress components with gzip
• ycsstop–Put CSS at top
• yjsbottom–Put JavaScript. at bottom
• yexpressions–Avoid CSS expressions
• yexternal–Make JavaScript. and CSS external
• ydns–Reduce DNS lookups
• yminify–Minify JavaScript. and CSS
• yredirects–Avoid URL redirects
• ydupes–Remove duplicate JavaScript. and CSS
• yetags–Configure entity tags (ETags)
• yxhr–Make AJAX cacheable
• yxhrmethod–Use GET for AJAX requests
• ymindom–Reduce the number of DOM elements
• yno404–Avoid HTTP 404 (Not Found) error
• ymincookie–Reduce cookie size
• ycookiefree–Use cookie-free domains
• ynofilter–Avoid AlphaImageLoader filter
• yimgnoscale–Do not scale images in HTML
• yfavicon–Make favicon small and cacheable

Once again, to configure YSlow to send your data to a beacon, you need to set a couple configuration parameters onabout:configpage of your browser:

for YSlow 1.x

• extensions.firebug.yslow.beaconUrl =http://www.showslow.com/beacon/yslow/
• extensions.firebug.yslow.optinBeacon =true

for YSlow 2.x

• extensions.firebug.yslow.beaconUrl =http://www.showslow.com/beacon/yslow/
• extensions.firebug.yslow.optinBeacon =true
  

reference
https://wiki.mozilla.org/Webdev:Cesium:Beacons
http://www.sergeychernyshev.com/blog/tools-of-the-trade-meeting-was-a-good-start/
http://code.google.com/p/page-speed/wiki/DownloadPageSpeed?tm=2