Editing Bidirectional text (section)

==== Marks ====
{{see also|Right-to-left mark|Left-to-right mark|Arabic letter mark}}
If a "weak" character is followed by another "weak" character, the algorithm will look at the first neighbouring "strong" character. Sometimes this leads to unintentional display errors. These errors are corrected or prevented with "pseudo-strong" characters. Such [[Unicode control characters]] are called ''marks''. The mark ({{unichar|200E|Left-to-right mark|note=LRM}} or {{unichar|200F|Right-to-left mark|note=RLM}}) is to be inserted into a location to make an enclosed weak character inherit its writing direction.

For example, to correctly display the {{unichar|2122|trade mark sign}} for an English name brand (LTR) in an Arabic (RTL) passage, an LRM mark is inserted after the trademark symbol if the symbol is not followed by LTR text (e.g. "{{lang|ar|قرأ Wikipedia™&lrm; طوال اليوم.|rtl=yes}}"). If the LRM mark is not added, the weak character ™ will be neighbored by a strong LTR character and a strong RTL character. Hence, in an RTL context, it will be considered to be RTL, and displayed in an incorrect order (e.g. "{{lang|ar|قرأ Wikipedia™ طوال اليوم.|rtl=yes}}").