---
title: Core Text Constants
framework: Core Text
role: collectionGroup
role_heading: API Collection
path: coretext/core-text-constants
---

# Core Text Constants

## Topics

### Constants

- [ATSFONTREF_DEFINED](coretext/atsfontref_defined.md)
- [kBSLNIdeographicHighBaseline](coretext/kbslnideographichighbaseline.md)
- [kCTAdaptiveImageProviderAttributeName](coretext/kctadaptiveimageproviderattributename.md)
- [kCTBackgroundColorAttributeName](coretext/kctbackgroundcolorattributename.md)
- [kCTBaselineClassAttributeName](coretext/kctbaselineclassattributename.md)
- [kCTBaselineClassHanging](coretext/kctbaselineclasshanging.md)
- [kCTBaselineClassIdeographicCentered](coretext/kctbaselineclassideographiccentered.md)
- [kCTBaselineClassIdeographicHigh](coretext/kctbaselineclassideographichigh.md)
- [kCTBaselineClassIdeographicLow](coretext/kctbaselineclassideographiclow.md)
- [kCTBaselineClassMath](coretext/kctbaselineclassmath.md)
- [kCTBaselineClassRoman](coretext/kctbaselineclassroman.md)
- [kCTBaselineInfoAttributeName](coretext/kctbaselineinfoattributename.md)
- [kCTBaselineOriginalFont](coretext/kctbaselineoriginalfont.md)
- [kCTBaselineReferenceFont](coretext/kctbaselinereferencefont.md)
- [kCTBaselineReferenceInfoAttributeName](coretext/kctbaselinereferenceinfoattributename.md)
- [kCTFontCollectionDisallowAutoActivationOption](coretext/kctfontcollectiondisallowautoactivationoption.md)
- [kCTFontCollectionIncludeDisabledFontsOption](coretext/kctfontcollectionincludedisabledfontsoption.md)
- [kCTFontDescriptorMatchingCurrentAssetSize](coretext/kctfontdescriptormatchingcurrentassetsize.md)
- [kCTFontDescriptorMatchingDescriptors](coretext/kctfontdescriptormatchingdescriptors.md)
- [kCTFontDescriptorMatchingError](coretext/kctfontdescriptormatchingerror.md)
- [kCTFontDescriptorMatchingPercentage](coretext/kctfontdescriptormatchingpercentage.md)
- [kCTFontDescriptorMatchingResult](coretext/kctfontdescriptormatchingresult.md)
- [kCTFontDescriptorMatchingSourceDescriptor](coretext/kctfontdescriptormatchingsourcedescriptor.md)
- [kCTFontDescriptorMatchingTotalAssetSize](coretext/kctfontdescriptormatchingtotalassetsize.md)
- [kCTFontDescriptorMatchingTotalDownloadedSize](coretext/kctfontdescriptormatchingtotaldownloadedsize.md)
- [kCTFontDownloadableAttribute](coretext/kctfontdownloadableattribute.md)
- [kCTFontDownloadedAttribute](coretext/kctfontdownloadedattribute.md)
- [kCTFontManagerBundleIdentifier](coretext/kctfontmanagerbundleidentifier.md)
- [kCTFontManagerErrorDomain](coretext/kctfontmanagererrordomain.md)
- [kCTFontManagerErrorFontAssetNameKey](coretext/kctfontmanagererrorfontassetnamekey.md)
- [kCTFontManagerErrorFontDescriptorsKey](coretext/kctfontmanagererrorfontdescriptorskey.md)
- [kCTFontManagerErrorFontURLsKey](coretext/kctfontmanagererrorfonturlskey.md)
- [kCTFontManagerRegisteredFontsChangedNotification](coretext/kctfontmanagerregisteredfontschangednotification.md)
- [kCTFontOpenTypeFeatureTag](coretext/kctfontopentypefeaturetag.md)
- [kCTFontOpenTypeFeatureValue](coretext/kctfontopentypefeaturevalue.md)
- [kCTFontOpticalSizeAttribute](coretext/kctfontopticalsizeattribute.md)
- [kCTFontRegistrationUserInfoAttribute](coretext/kctfontregistrationuserinfoattribute.md)
- [kCTFontTableAnkr](coretext/kctfonttableankr.md)
- [kCTFontTableLtag](coretext/kctfonttableltag.md)
- [kCTFontTableMATH](coretext/kctfonttablemath.md)
- [kCTFontVariationAxesAttribute](coretext/kctfontvariationaxesattribute.md)
- [kCTHorizontalInVerticalFormsAttributeName](coretext/kcthorizontalinverticalformsattributename.md)
- [kCTLanguageAttributeName](coretext/kctlanguageattributename.md)
- [kCTRubyAnnotationAttributeName](coretext/kctrubyannotationattributename.md)
- [kCTRubyAnnotationScaleToFitAttributeName](coretext/kctrubyannotationscaletofitattributename.md)
- [kCTRubyAnnotationSizeFactorAttributeName](coretext/kctrubyannotationsizefactorattributename.md)
- [kCTVersionNumber10_10](coretext/kctversionnumber10_10.md)
- [kCTVersionNumber10_11](coretext/kctversionnumber10_11.md)
- [kCTVersionNumber10_12](coretext/kctversionnumber10_12.md)
- [kCTVersionNumber10_13](coretext/kctversionnumber10_13.md)
- [kCTVersionNumber10_14](coretext/kctversionnumber10_14.md)
- [kCTVersionNumber10_15](coretext/kctversionnumber10_15.md)
- [kCTVersionNumber10_5_2](coretext/kctversionnumber10_5_2.md)
- [kCTVersionNumber10_5_3](coretext/kctversionnumber10_5_3.md)
- [kCTVersionNumber10_5_5](coretext/kctversionnumber10_5_5.md)
- [kCTVersionNumber10_5](coretext/kctversionnumber10_5.md)
- [kCTVersionNumber10_6](coretext/kctversionnumber10_6.md)
- [kCTVersionNumber10_7](coretext/kctversionnumber10_7.md)
- [kCTVersionNumber10_8](coretext/kctversionnumber10_8.md)
- [kCTVersionNumber10_9](coretext/kctversionnumber10_9.md)
- [kCTVersionNumber11_0](coretext/kctversionnumber11_0.md)
- [kCTWritingDirectionAttributeName](coretext/kctwritingdirectionattributename.md)
- [kCTWritingDirectionEmbedding](coretext/kctwritingdirectionembedding.md)
- [kCTWritingDirectionOverride](coretext/kctwritingdirectionoverride.md)
- [kKERXDescending](coretext/kkerxdescending.md)
- [kKERXValuesAreLong](coretext/kkerxvaluesarelong.md)
- [kLanguageTagType](coretext/klanguagetagtype.md)
- [kLTAGCurrentVersion](coretext/kltagcurrentversion.md)
- [kMORXCoverLogicalOrder](coretext/kmorxcoverlogicalorder.md)
- [kSTKCrossStreamReset](coretext/kstkcrossstreamreset.md)

## See Also

### Reference

- [Styling Attributed Strings](coretext/styling-attributed-strings.md)
- [Core Text Structures](coretext/core-text-structures.md)
- [Core Text Enumerations](coretext/core-text-enumerations.md)
- [Core Text Functions](coretext/core-text-functions.md)
- [Core Text Data Types](coretext/core-text-data-types.md)
- [SFNT Support](coretext/sfnt-support.md)