Check out the new Rules School story covering the Mando rule just posted today on the PDGA home page: http://www.pdga.com/mandatories
You can re-tee any tee shot no matter where it lands by calling the unplayble rule and getting a penalty. However, if you missed a mando or landed above 2-meters when the rule is in effect, you have to accept that penalty first before also accepting the unplayable lie penalty to re-tee.