I have a line with two 2 attributes. I would like to display both information along with the line in frequent interval, one info above the line and the other is below the line. I am working in QGIS 1.8.0-Lisboa software.
You can label the first attribute above the line using the usual way, then duplicate the layer and change the labelling to beneath the line.
I`m not sure if this was already implemented in Lisboa. If not, I suggest an update to QGIS 2.2
Alternatively, you can make a label across 2 lines with something like
"operator" || '/n' || "ref" , centered on the line. You have to add the
/n separator in the Formatting tab.