>>1
Symbolic Expression ``Code''.
It's a BBCode substitute that uses a derivative of S-Expressions:
{b.u.i.o EXPERT {s {sup S{sup e}}{sub x{sub p}}}{code Code}r}
Becomes:
[b][u][i][o]EXPERT [s][sup]S[sup]e[/sup][/sup][sub]x[sub]p[/sub][/sub][/s][code]Code[/code]r[/o][/i][/u][/b]
EXPERT SexpCoder