optional. If not NULL, its value is used as style in the
document that will be used to build entries of the TOC.
seq_id
optional. If not NULL, its value is used as sequence
identifier in the document that will be used to build entries of the
TOC. See also run_autonum() to specify a sequence identifier.
separator
optional. Some configurations need "," (i.e. from Canada) separator instead of ";"