There was a question on the forums about calling the XenApp task Connect To Farm when using a domain user name. Since we are using PowerShell heavily under the covers the string passed in to this task for the username needs to use the PowerShell escape character whenever a reserved character for PowerShell is in the string. I searched Microsoft's site, but couldn't find much detail out there on this so I wanted to clarify here:

The escape character for PowerShell is the grave-accent character "`" (which on US keyboards should be in the upper-left of the keyboard to the left of the number 1.

I haven't been able to find much posted on reserved characters on Microsoft's site, but here is a good article that highlights what is in the PowerShell help documentation:

http://www.microsoft.com/technet/scriptcenter/resources/qanda/jan08/hey0117.mspx

Here is the list of characters from that article:

$
( )
*
+
.
[ ]
?
\
/
^
{ }
|

 If you need to use any of those characters in a string then you will need to escape it with the ` character. For example, to pass in a domain username to Connect to Farm in XenApp then you will need to pass in "domain`/user" instead of just typing "domain/user".