VectorColorFunctionScaling is an option for graphics functions which specifies whether arguments supplied to a vector color function should be scaled to lie between 0 and 1.
VerifyConvergence is an option to Sum, NSum, and similar functions that specifies whether convergence checking should be done.
WaveletFilterCoefficients[wave, filt] gives the filter coefficients for the symbolic wavelet wave of type filt.
XMLElement[tag, {attr_1 -> val_1, ...}, {data_1, ...}] represents an element in symbolic XML.
$ByteOrdering gives the native ordering of bytes in binary data on your computer system.
$ExportFormats gives a list of export formats currently supported in your Mathematica system.
$FrontEndSession is a global symbol that represents the current session of the front end from which the kernel is being run.
$Post
(Built-in Mathematica Symbol) $Post is a global variable whose value, if set, is applied to every output expression.
$SystemID is a short string that identifies the type of computer system on which Mathematica is being run.
$TemporaryDirectory gives the main system directory for temporary files on your computer system.