From the ARRL Operating Manual (2003):

Chapter 3, FM The Friendly Mode, in a paragraph marked “Go Simplex” it says, among other things:

“After you’ve made a contact on a repeater, move the conversation to a simplex frequency, if possible. The function of a repeater is to provide communications between stations not able to communicate directly because of terrain or equipment limitations. If stations are able to communicate without a repeater, they should always use simplex when ever possible so the repeater will be available for stations that need its facilities.” p.3-10

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