Hog-Morse was the tendency of inexperienced telegraph operators to make errors when sending or receiving in Morse code. It is so called after one example, "home" (▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄) becoming "hog" (▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄), which is just a subtle error in timing. The term was current in the US in the period when American Morse code was in use.
The American code was a little different to the International Morse Code currently in use. With the American code it is easier to make timing errors of this sort because there were several more symbol timings than there are in the international code. For instance, the international code has only two symbols, dots and dashes, but the American code has several lengths of dash. There is a distinction between "L" (▄▄▄▄▄▄▄) and "T" (▄▄▄▄▄). Also, in the international code the space between symbols within a character is always the same, but American Morse has two different spaces. The letters "S" (▄▄▄▄▄▄▄▄), "C" (▄▄▄▄▄▄▄▄▄), and "R" (▄▄▄▄▄▄▄▄▄) all consist of three dots, but the timing is different in each case.
A frequently quoted, but possibly apocryphal, story from the historical period concerns the similarity of "L" and "T" in the American code. A company in Richmond, Virginia received a request for quotation for a load of "undressed staves" (rough sawn wood intended for the manufacture of barrels), but the telegraph operator had sent ▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄ (SLAVES) instead of ▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄ (STAVES) thus attempting to order "undressed slaves". The company replied reminding the customer that slavery had been abolished.
Another example given in the literature is "please fill me in" becoming "6naz fimme q". One commentator has called this the 19th century autocorrect.