After lots of head scratching, I discovered that many of the icons listed on materialdesignicons.com haven't actually been released yet...
Is there a way to filter that list by icons that are currently able to be used? Or maybe that site should only display icons that are part of the latest release.
All the icons included in the current release are listed in the preview.html file bundled with the webfont, which can also be accessed on the CDN.
As well as that, you can use the history page or the sandbox to see which icons were added since the last release.
The new website will be able to filter by version release and latest icons. The current site lacks that functionality. Right now the CDN/preview.html bundled in the release is the best view or use the chrome/firefox extension.
https://chrome.google.com/webstore/detail/materialdesignicons-picke/edjaedpifkihpjkcgknfokmibkoafhme
http://cdn.materialdesignicons.com/2.0.46/meta.json Contains all the meta data for the release also, but not very friendly to look at.
Closing this issue since it will be resolved in the new site.