A character with the property Grapheme_Base, or any standard Korean syllable block.

• Characters with the property Grapheme_Base include all base characters (with the exception of U+FF9E..U+FF9F) plus most spacing marks.
• The concept of a grapheme base is introduced to simplify discussion of the graphical application of nonspacing marks to other elements of text. A grapheme base may consist of a spacing (combining) mark, which distinguishes it from a base character per se. A grapheme base may also itself consist of a sequence of characters, in the case of the standard Korean syllable block.