reftex-toggle-auto-view-crossref
reftex-toggle-auto-view-crossref is an interactive autoloaded Lisp function in `reftex-dcr.el
'.
(reftex-toggle-auto-view-crossref)
Toggle the automatic display of crossref information in the echo area.
When active, leaving point idle in the argument of a \ref or \cite macro
will display info in the echo area.