The package extends the LaTeX labelling system: whenever a label is set, the values of counters (selected by the user) are recorded, along with the label. The value of these counters can be recalled with a command similar to \pageref.

The package also adds commands \s[name]ref (for each counter [name] that the user has selected); these commands display something only if the value of the [name] counter is changed from when the label was set. Many commands are provided to serve as a macro programming environment for using the extended labels.

See also zref.

The author is Giuseppe Bilotta.