The section sign (§; Unicode U+00A7, HTML entity §) is a typographical character used mainly to refer to a particular section of a document, such as a legal code. It is frequently used along with the pilcrow (¶), or paragraph sign. When duplicated, as §§, it is read as the plural “sections” (§§ 13–21), unlike “$” (dollars) and much as “pp.” (pages) is the plural of “p.” (page) or “SS” for “saints”. For an effect comparable to the contemporary use of bold type, early scribes would double stroke letters, hence the sign was developed from a double stroked letter S.

Like the dagger (†) and double dagger (‡), it is also sometimes used to link to a footnote where the asterisk (*) is already in use on a given page; however, these usages are declining in favor of numbered footnotes, usually linked by a superscripted (or, decreasingly, square bracketed) number.

Perhaps everyone else in the world already knew what these symbols were called and what exactly they meant, but this came as somewhat of an epiphany to me.

I love that word, pilcrow. via wikipedia