A Comparative Analysis of Information Hiding Techniques for Copyright Protection of Text Documents

Table 2

Unicode zero-width control characters [11, 32, 33].

Unicode Hex code	HTML code	Name	Text written symbol
U+200B	​	Zero-width space	No symbol and width
U+200C	‌	Zero-width nonjoiner	No symbol and width
U+200D	‍	Zero-width joiner	No symbol and width
U+200E	‎	Left-to-right mark	No symbol and width
U+202D	‭	Left-to-right override	No symbol and width
U+202E	‮	Right-to-left override	No symbol and width
U+202A	‪	Left-to-right embedding	No symbol and width
U+202B	‫	Right-to-left embedding	No symbol and width
U+202C	‬	Pop-directional formatting	No symbol and width
U+180E	᠎	Mongolian-vowel separator	No symbol and width