This simplified spelling appears to be related to the formality of the context.In every case that a serekh is shown on a work of stone, or an official seal impression, it has both symbols.
Ka’s inscriptions have been found in three sites in Lower Egypt and one in Canaan.
This must be compared to Narmer, whose serekhs have been found in ten sites in Lower Egypt and nine sites in Canaan (see discussion in “Tomb and Artifacts” section).
In addition, two necropolis seals from Abydos show the name in a unique way: While the chisel is shown conventionally where the catfish would be expected, there is a symbol that has been interpreted by several scholars as an animal skin. Narmer is often credited with the unification of Egypt by means of the conquest of Lower Egypt by Upper Egypt.
The Petrie Museum of Egyptian Archaeology, London, exhibits a limestone head of an early Egyptian king which the Museum identifies as being a depiction of Narmer on the basis of the similarity (according to Petrie Although highly inter-related, the questions of “who was Menes? While Menes is traditionally considered the first king of Ancient Egypt, Narmer has been identified by the majority of Egyptologists as the same person as Menes.
Narmer's identity is the subject of ongoing debates, although the dominant opinion among Egyptologists identifies Narmer with the pharaoh Menes, who is renowned in the ancient Egyptian written records as the first king, and the unifier of Ancient Egypt.