http://msdn.microsoft.com/en-us/library/e1f13641.aspx
<httpRuntime
apartmentThreading = "[True|False]"
appRequestQueueLimit = "number"
delayNotificationTimeout = "number"
enable = "[True|False]"
enableHeaderChecking = "[True|False]"
enableKernelOutputCache = "[True|False]"
enableVersionHeader = "[True|False]"
encoderType = "string"
executionTimeout = "number"
maxQueryStringLength = "number"
maxRequestLength = "number"
maxUrlLength = "number"
maxWaitChangeNotification = "number"
minFreeThreads = "number"
minLocalRequestFreeThreads = "number"
relaxedUrlToFileSystemMapping = "[True|False]"
requestLengthDiskThreshold = "number"
requestPathInvalidCharacters = "string"
requestValidationMode = "[2.0|4.0]"
requestValidationType = "string"
requireRootedSaveAsPath = "[True|False]"
sendCacheControlHeader = "[True|False]"
shutdownTimeout = "number"
useFullyQualifiedRedirectUrl = "[True|False]"
waitChangeNotification = "number" />