In early March 2016, AT&T and its executives learned that a steeper-than-expected decline in smartphone sales by AT&T would cause its revenue for the first quarter of 2016 ("1Q16") to fall short of analysts’ estimates. Fearful of a revenue miss at the end of the quarter, AT&T’s Chief Financial Officer instructed AT&T’s IR Department to "work[] the analysts who still have equipment revenue too high."
Describe what rule AT&T violated with their actions below and specifically why.