F/I meaning in Electronics ?

"Our Hitch in Hell" is a ballad by American poet Frank Bernard Camp, originally published as one of 49 ballads in a 1917 collection entitled American Soldier Ballads, that went on to inspire multiple variants among American law enforcement and military, either as The Final Inspection, the Soldier's Prayer (or Poem), the Policeman's Prayer (or Poem), and variations on those titles.

The final lines of the poem speak of the protagonist being automatically accepted into Heaven due to having already served time in Hell, Hell being their military service:

In his 1949 work The Struggle for Guadalcanal, military historian Samuel Eliot Morison transcribed a Marine variant of the poem (possibly authored by James A. Donohue) from the epitaph on the Lunga Point Cemetery grave of Private First Class Bill Anderson, who had died in that battle: