The REL attribute in HTML is a shortened version of "relationship." REL attributes are used to define the relationship between one file and another.

if vanpiers rel then why dont people talk about them.

'rel pref' could be short for RELIGIOUS PREFERENCE..................

protons --- rel. mass 1 amu, rel. charge +1, location in the nucleus.

neutrons --- rel. mass 1 amu, rel. charge 0, location in the nucleus.

electrons --- rel. mass 0 amu, rel. charge -1, location outside the nucleus.