Abstract
In the note we study Legendrian and transverse knots in rationally
null-homologous knot types. In particular we generalize the standard
definitions of self-linking number, Thurston-Bennequin invariant and rotation
number. We then prove a version of Bennequin's inequality for these knots and
classify precisely when the Bennequin bound is sharp for fibered knot types.
Finally we study rational unknots and show they are weakly Legendrian and
transversely simple.
This version of the paper corrects the definition of rational self-linking
number in the previous and published version of the paper. With this correction
all the main results of the paper remain true as originally stated.