Boundary is the boundary between characters (including non-printing characters)
Boundary is the linefeed, or return character.
Boundary is the initial character of the content or a character immediately following a newline, linefeed, or return character.
Boundary is the last (terminal) character in a sentence; in languages which use "sentence stop" punctuation such as English, the boundary is thus the '.', '?', or similar terminal punctuation character.
Boundary is the first character in a sentence.
Boundary is the end (i.e. last character) of a word.
Boundary is the start (i.e. first character) of a word.
Text boundary types used for specifying boundaries for regions of text. This enumeration is deprecated since 2.9.4 and should not be used. Use AtkTextGranularity with #atk_text_get_string_at_offset instead.