To create musical symbols, the text must be surrounded in tags, like this:

[mus]text to "musify"[/mus].

This should be familiar to those who are used to using BBcode in forums (where you type [b]text[/b] to embolden text and so on).

Some things don't require the tags: for example if you were writing Cm | F then the tags would be unnecessary. But C♯m | F♯ would need them. If you learn the syntax you can write what you want and then put the tags in after you've finished writing the content.

As an example, let's look at the first sixteen bars of the Lerner and Loewe song On The Street Where You Live. Traditionally it's in cut time - two minims (half notes) per bar. I'd write out the sequence, using the codes first:

} B£[[6]] B£[[6]] F[[7]] | B£ | B£ F[[7]] |
B£[[maj7] | D£_ C((9)) | F[[7]] Cm[[7]] | F[[7]] |
Cm[[7]] Cm[[7]] E£m | B£ | Gm[[7]] | C[[7]] |
F[[7]] F+[[7]] | B£[[6]] | B£[[6]] Cm[[7]] F[[7]]

And then use the tags to wrap each line.

22 B♭⁶ | B♭⁶ F⁷ | B♭ | B♭ F⁷ |
B♭^maj7 | D♭^° C⁽⁹⁾ | F⁷ Cm⁷ | F⁷ |
Cm⁷ | Cm⁷ E♭m | B♭ | Gm⁷ |
C⁷ | F⁷ F+⁷ | B♭⁶ | B♭⁶ Cm⁷ F⁷