*
The fact that there are two omicrons leads one to suspect that somewhere
along the way a cataloguer misread an English "o" for a Greek
omicron.
Both Vela and Puppis have many English letters, upper case and lower
case. If one studies Tirion's SkyAtlas 2000.0, one discovers that Vela
has both a Greek omicron and an English "o", while Puppis has no English "o"
but does have a Greek omicron.
Therefore I suspect that omicron Puppis was originally an English "o"
and was misread some time ago into a Greek omicron, and the label has
stuck.