What is "macron below"

n. A diacritical mark whose appearance is of a macron, and is placed below the letter.

A̱a̱ḆḇC̱c̱

Macron below, , is a combining diacritical mark used in various orthographies.

It is not to be confused with " combining minus below" ̠ (U+0320), " combining low line" ̲̲ (U+0332) and "low line" (" underscore") _ ). The difference between "macron below" and "low line" is that the latter will result in an unbroken underline when run together, compare a̱ḇc̱ vs. a̲b̲c̲ (of which only the latter should look like abc).

Note that the Unicode names of composed characters whose decompositions contain this character misleadingly have "line below" rather than "macron below". Thus, ḇ "Latin small letter b with line below" decomposes to "Latin small letter b" and "combining macron below".