Legend: (from http://msdn.microsoft.com/en-us/library/windows/desktop/cc144101%28v=vs.85%29.aspx)
%* - replace with all parameters
%~ - replace with all parameters starting with and following the second parameter
%0 or %1 the first file parameter. For example "C:\Users\Eric\Destop\New Text Document.txt". Generally this should be in quotes and the applications command line parsing should accept quotes to disambiguate files with spaces in the name and different command line parameters (this is a security best practice and I believe mentioned in MSDN).
%<n> (where N is 2 - 9), replace with the nth parameter
%s - show command
%h - hotkey value
%i - IDList stored in a shared memory handle is passed here.
%l - long file name form of the first parameter. Note win32 applications will be passed the long file name, win16 applications get the short file name. Specifying %L is preferred as it avoids the need to probe for the application type.
%d - desktop absolute parsing name of the first parameter (for items that don't have file system paths)
%v - for verbs that are none implies all, if there is no parameter passed this is the working directory
%w - the working directory
dht is handled by:
  "C:\Progs\Azureus\Azureus.exe" "%1"
http is handled by:
  "D:\Progs\Minefield\firefox.exe" -osint -url "%1"
rlogin is handled by:
  "C:\Windows\System32\rundll32.exe" "C:\Windows\System32\url.dll",TelnetProtocolHandler %l
firefoxurl is handled by:
  "D:\Progs\Minefield\firefox.exe" -osint -url "%1"
ie.http is handled by:
  "C:\Program Files\Internet Explorer\iexplore.exe" %1
windowsmediacenterssl is handled by:
  C:\Windows\ehome\MediaCenterWebLauncher.exe -ssl "%1"
windowsmediacenterapp is handled by:
  C:\Windows\ehome\MediaCenterWebLauncher.exe -app "%1"
bctp is handled by:
  "C:\Progs\Azureus\Azureus.exe" "%1"
ie.https is handled by:
  "C:\Program Files\Internet Explorer\iexplore.exe" %1
explorer.assocprotocol.search-ms is handled by:
  %SystemRoot%\Explorer.exe /separate,/idlist,%I,%L
mms is handled by:
  "%ProgramFiles(x86)%\Windows Media Player\wmplayer.exe" "%L"
telnet is handled by:
  "C:\Windows\System32\rundll32.exe" "C:\Windows\System32\url.dll",TelnetProtocolHandler %l
search-ms is handled by:
  %SystemRoot%\Explorer.exe /separate,/idlist,%I,%L
windowsmediacenterweb is handled by:
  C:\Windows\ehome\MediaCenterWebLauncher.exe -web "%1"
search is handled by:
  %SystemRoot%\Explorer.exe /separate,/idlist,%I,%L
wmp11.assocprotocol.mms is handled by:
  "%ProgramFiles(x86)%\Windows Media Player\wmplayer.exe" "%L"
tn3270 is handled by:
  "C:\Windows\System32\rundll32.exe" "C:\Windows\System32\url.dll",TelnetProtocolHandler %l
https is handled by:
  "D:\Progs\Minefield\firefox.exe" -osint -url "%1"
ldap is handled by:
  "%ProgramFiles%\Windows Mail\wab.exe" "/ldap:%1"
bc is handled by:
  "C:\Progs\Azureus\Azureus.exe" "%1"
ctsu is handled by:
  "C:\Program Files (x86)\Creative\Shared Files\Software Update\AutoUpdate.exe"
ftp is handled by:
  "D:\Progs\Minefield\firefox.exe" -osint -url "%1"
mailto is handled by:
  "C:\Progs\Thunderbird\thunderbird.exe" -osint -compose "%1"
magnet is handled by:
  "C:\Progs\Azureus\Azureus.exe" "%1"
ie.ftp is handled by:
  "C:\Program Files\Internet Explorer\iexplore.exe" %1
