San Miguel Mixtepec is referenced in this entry and listed as ISO [zpm]. However [zpm] is the code for the Mixtepecs of the Miahuatlan districts. San Miguel Mixtepec and its neighbor San Mateo Mixtepec are part of West Zapotec (Totomachapan, Los Altos, Lachixio). They should be [zpp], which is where the look given innovations and retentions or [zpl] with which SIL tested slightly higher intelligibility.
We have now looked into this issue with San Miguel Mixtepec. The appended ISO code [zpm] is erroneous and will be removed in the 18th edition of the Ethnologue. Based on information we have received from SIL-Mexico, we will also revise the location and intelligibility statements for Lachixio [zpl].