Why is memory section nomenclature prefixed with a '.'

Question

The memory sections of an application are typically named as follows:

.text, .data, .bss, ...

My question is, what is the history behind the '.' prefix (why .text and not text)?

Answer 1

My best guess is that it with no . the words would be seen as labels (I.e. points to jump to) rather than assembler directives.