The \ m sequence refers to the 'meta' key (special on some keyboards, or usually the Alt key or the Escape key).

m序列引用“Meta”键(某些键盘上的专用键，或者通常为alt键或escape键)。

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Characters with codes higher than 127 will be preceded with m - as in "meta", which is an equivalent of Alt - characters on other systems.

对于代码大于127的字符，它们的前面将会被加上m -(表示“meta”)，这与其它系统中在字符前面加上Alt -相当。

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