Prototypical; preceding the proper beginning of something(adjective)
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Use "proto" in a sentence
"True if the packet is an IP multicast packet. ip6 multicast True if the packet is an IPv6 multicast packet. ether proto protocol True if the packet is of ether type proto col."
"Packets truncated because of a limited snapshot are indicated in the output with ` ` [| proto] '', where proto is the name of the proto col level at which the truncation has occurred."
"He presents a sequence of “three principal stages in the development of human thinking,” which he calls proto-logical, empirico-logical and logical."