# Core Foundation Constants ## Topics ### Constants [`var CFByteOrderBigEndian: __CFByteOrder`](/documentation/CoreFoundation/CFByteOrderBigEndian) Multi-byte values are stored with the most-significant bytes stored first. PowerPC CPUs are big endian. [`var CFByteOrderLittleEndian: __CFByteOrder`](/documentation/CoreFoundation/CFByteOrderLittleEndian) Multi-byte values are stored with the least-significant bytes stored first. Pentium CPUs are little endian. [`var CFByteOrderUnknown: __CFByteOrder`](/documentation/CoreFoundation/CFByteOrderUnknown) The byte order is unknown. [`var kCFCoreFoundationVersionNumber10_10: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber10_10) [`var kCFCoreFoundationVersionNumber10_10_1: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber10_10_1) [`var kCFCoreFoundationVersionNumber10_10_2: Int32`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber10_10_2) [`var kCFCoreFoundationVersionNumber10_10_3: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber10_10_3) [`var kCFCoreFoundationVersionNumber10_10_4: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber10_10_4) [`var kCFCoreFoundationVersionNumber10_10_5: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber10_10_5) [`var kCFCoreFoundationVersionNumber10_10_Max: Int32`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber10_10_Max) [`var kCFCoreFoundationVersionNumber10_11: Int32`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber10_11) [`var kCFCoreFoundationVersionNumber10_11_1: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber10_11_1) [`var kCFCoreFoundationVersionNumber10_11_2: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber10_11_2) [`var kCFCoreFoundationVersionNumber10_11_3: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber10_11_3) [`var kCFCoreFoundationVersionNumber10_11_4: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber10_11_4) [`var kCFCoreFoundationVersionNumber10_11_Max: Int32`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber10_11_Max) [`var kCFCoreFoundationVersionNumber10_7_5: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber10_7_5) [`var kCFCoreFoundationVersionNumber10_8: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber10_8) [`var kCFCoreFoundationVersionNumber10_8_1: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber10_8_1) [`var kCFCoreFoundationVersionNumber10_8_2: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber10_8_2) [`var kCFCoreFoundationVersionNumber10_8_3: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber10_8_3) [`var kCFCoreFoundationVersionNumber10_8_4: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber10_8_4) [`var kCFCoreFoundationVersionNumber10_9: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber10_9) [`var kCFCoreFoundationVersionNumber10_9_1: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber10_9_1) [`var kCFCoreFoundationVersionNumber10_9_2: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber10_9_2) [`var kCFCoreFoundationVersionNumber_iOS_6_0: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber_iOS_6_0) [`var kCFCoreFoundationVersionNumber_iOS_6_1: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber_iOS_6_1) [`var kCFCoreFoundationVersionNumber_iOS_7_0: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber_iOS_7_0) [`var kCFCoreFoundationVersionNumber_iOS_7_1: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber_iOS_7_1) [`var kCFCoreFoundationVersionNumber_iOS_8_0: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber_iOS_8_0) [`var kCFCoreFoundationVersionNumber_iOS_8_1: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber_iOS_8_1) [`var kCFCoreFoundationVersionNumber_iOS_8_2: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber_iOS_8_2) [`var kCFCoreFoundationVersionNumber_iOS_8_3: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber_iOS_8_3) [`var kCFCoreFoundationVersionNumber_iOS_8_4: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber_iOS_8_4) [`var kCFCoreFoundationVersionNumber_iOS_8_x_Max: Int32`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber_iOS_8_x_Max) [`var kCFCoreFoundationVersionNumber_iOS_9_0: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber_iOS_9_0) [`var kCFCoreFoundationVersionNumber_iOS_9_1: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber_iOS_9_1) [`var kCFCoreFoundationVersionNumber_iOS_9_2: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber_iOS_9_2) [`var kCFCoreFoundationVersionNumber_iOS_9_3: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber_iOS_9_3) [`var kCFCoreFoundationVersionNumber_iOS_9_4: Double`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber_iOS_9_4) [`var kCFCoreFoundationVersionNumber_iOS_9_x_Max: Int32`](/documentation/CoreFoundation/kCFCoreFoundationVersionNumber_iOS_9_x_Max) [`var kCFNotFound: CFIndex`](/documentation/CoreFoundation/kCFNotFound) A constant that indicates that a search operation did not succeed in locating the target value. [`let kCFURLAddedToDirectoryDateKey: CFString!`](/documentation/CoreFoundation/kCFURLAddedToDirectoryDateKey) [`let kCFURLApplicationIsScriptableKey: CFString!`](/documentation/CoreFoundation/kCFURLApplicationIsScriptableKey) [`let kCFURLCanonicalPathKey: CFString!`](/documentation/CoreFoundation/kCFURLCanonicalPathKey) [`let kCFURLDocumentIdentifierKey: CFString!`](/documentation/CoreFoundation/kCFURLDocumentIdentifierKey) [`let kCFURLFileProtectionComplete: CFString!`](/documentation/CoreFoundation/kCFURLFileProtectionComplete) [`let kCFURLFileProtectionCompleteUnlessOpen: CFString!`](/documentation/CoreFoundation/kCFURLFileProtectionCompleteUnlessOpen) [`let kCFURLFileProtectionCompleteUntilFirstUserAuthentication: CFString!`](/documentation/CoreFoundation/kCFURLFileProtectionCompleteUntilFirstUserAuthentication) [`let kCFURLFileProtectionKey: CFString!`](/documentation/CoreFoundation/kCFURLFileProtectionKey) [`let kCFURLFileProtectionNone: CFString!`](/documentation/CoreFoundation/kCFURLFileProtectionNone) [`let kCFURLGenerationIdentifierKey: CFString!`](/documentation/CoreFoundation/kCFURLGenerationIdentifierKey) [`let kCFURLIsApplicationKey: CFString!`](/documentation/CoreFoundation/kCFURLIsApplicationKey) [`let kCFURLQuarantinePropertiesKey: CFString!`](/documentation/CoreFoundation/kCFURLQuarantinePropertiesKey) [`let kCFURLTagNamesKey: CFString!`](/documentation/CoreFoundation/kCFURLTagNamesKey) [`let kCFURLUbiquitousItemDownloadingErrorKey: CFString!`](/documentation/CoreFoundation/kCFURLUbiquitousItemDownloadingErrorKey) [`let kCFURLUbiquitousItemDownloadingStatusCurrent: CFString!`](/documentation/CoreFoundation/kCFURLUbiquitousItemDownloadingStatusCurrent) [`let kCFURLUbiquitousItemDownloadingStatusDownloaded: CFString!`](/documentation/CoreFoundation/kCFURLUbiquitousItemDownloadingStatusDownloaded) [`let kCFURLUbiquitousItemDownloadingStatusKey: CFString!`](/documentation/CoreFoundation/kCFURLUbiquitousItemDownloadingStatusKey) [`let kCFURLUbiquitousItemDownloadingStatusNotDownloaded: CFString!`](/documentation/CoreFoundation/kCFURLUbiquitousItemDownloadingStatusNotDownloaded) [`let kCFURLUbiquitousItemUploadingErrorKey: CFString!`](/documentation/CoreFoundation/kCFURLUbiquitousItemUploadingErrorKey) [`let kCFURLVolumeIsEncryptedKey: CFString!`](/documentation/CoreFoundation/kCFURLVolumeIsEncryptedKey) [`let kCFURLVolumeIsRootFileSystemKey: CFString!`](/documentation/CoreFoundation/kCFURLVolumeIsRootFileSystemKey) [`let kCFURLVolumeSupportsCompressionKey: CFString!`](/documentation/CoreFoundation/kCFURLVolumeSupportsCompressionKey) [`let kCFURLVolumeSupportsExclusiveRenamingKey: CFString!`](/documentation/CoreFoundation/kCFURLVolumeSupportsExclusiveRenamingKey) [`let kCFURLVolumeSupportsFileCloningKey: CFString!`](/documentation/CoreFoundation/kCFURLVolumeSupportsFileCloningKey) [`let kCFURLVolumeSupportsSwapRenamingKey: CFString!`](/documentation/CoreFoundation/kCFURLVolumeSupportsSwapRenamingKey) [`var CGFLOAT_EPSILON: Double`](/documentation/CoreFoundation/CGFLOAT_EPSILON) [`var CGFLOAT_IS_DOUBLE: Int32`](/documentation/CoreFoundation/CGFLOAT_IS_DOUBLE) [`var CGFLOAT_MAX: Double`](/documentation/CoreFoundation/CGFLOAT_MAX) [`var CGFLOAT_MIN: Double`](/documentation/CoreFoundation/CGFLOAT_MIN) [`var COREFOUNDATION_CFPLUGINCOM_SEPARATE: Int32`](/documentation/CoreFoundation/COREFOUNDATION_CFPLUGINCOM_SEPARATE) [`var ISA_PTRAUTH_DISCRIMINATOR: Int32`](/documentation/CoreFoundation/ISA_PTRAUTH_DISCRIMINATOR) [`let kCFErrorLocalizedFailureKey: CFString!`](/documentation/CoreFoundation/kCFErrorLocalizedFailureKey) [`let kCFURLDirectoryEntryCountKey: CFString!`](/documentation/CoreFoundation/kCFURLDirectoryEntryCountKey) [`let kCFURLFileContentIdentifierKey: CFString!`](/documentation/CoreFoundation/kCFURLFileContentIdentifierKey) [`let kCFURLFileIdentifierKey: CFString!`](/documentation/CoreFoundation/kCFURLFileIdentifierKey) [`let kCFURLFileProtectionCompleteWhenUserInactive: CFString!`](/documentation/CoreFoundation/kCFURLFileProtectionCompleteWhenUserInactive) [`let kCFURLIsPurgeableKey: CFString!`](/documentation/CoreFoundation/kCFURLIsPurgeableKey) [`let kCFURLIsSparseKey: CFString!`](/documentation/CoreFoundation/kCFURLIsSparseKey) [`let kCFURLMayHaveExtendedAttributesKey: CFString!`](/documentation/CoreFoundation/kCFURLMayHaveExtendedAttributesKey) [`let kCFURLMayShareFileContentKey: CFString!`](/documentation/CoreFoundation/kCFURLMayShareFileContentKey) [`let kCFURLUbiquitousItemIsExcludedFromSyncKey: CFString!`](/documentation/CoreFoundation/kCFURLUbiquitousItemIsExcludedFromSyncKey) [`let kCFURLVolumeAvailableCapacityForImportantUsageKey: CFString!`](/documentation/CoreFoundation/kCFURLVolumeAvailableCapacityForImportantUsageKey) [`let kCFURLVolumeAvailableCapacityForOpportunisticUsageKey: CFString!`](/documentation/CoreFoundation/kCFURLVolumeAvailableCapacityForOpportunisticUsageKey) [`let kCFURLVolumeMountFromLocationKey: CFString!`](/documentation/CoreFoundation/kCFURLVolumeMountFromLocationKey) [`let kCFURLVolumeSubtypeKey: CFString!`](/documentation/CoreFoundation/kCFURLVolumeSubtypeKey) [`let kCFURLVolumeSupportsAccessPermissionsKey: CFString!`](/documentation/CoreFoundation/kCFURLVolumeSupportsAccessPermissionsKey) [`let kCFURLVolumeSupportsFileProtectionKey: CFString!`](/documentation/CoreFoundation/kCFURLVolumeSupportsFileProtectionKey) [`let kCFURLVolumeSupportsImmutableFilesKey: CFString!`](/documentation/CoreFoundation/kCFURLVolumeSupportsImmutableFilesKey) [`let kCFURLVolumeTypeNameKey: CFString!`](/documentation/CoreFoundation/kCFURLVolumeTypeNameKey) [`let kCFUserNotificationAlertTopMostKey: CFString!`](/documentation/CoreFoundation/kCFUserNotificationAlertTopMostKey) [`let kCFUserNotificationKeyboardTypesKey: CFString!`](/documentation/CoreFoundation/kCFUserNotificationKeyboardTypesKey) --- Copyright © 2026 Apple Inc. 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