The Killian documents are widely considered to be fake. Starting with a Free Republic web posting by Harry MacDougald, a conservative Republican lawyer posting under the blogger name "Buckhead." MacDougald and multiple fellow bloggers claimed that the formatting shown in the documents used proportional fonts that did not come into common use until the mid-to-late 1990s and alleged that the documents were therefore likely forgeries. While the widely publicized rationale of "Buckhead" was technically inaccurate, both related and unrelated serious challenges to the authenticity of the documents nonetheless exist. For instance, it is unlikely that the typewriters available to Killian's secretary could have produced such a document, and the documents contained U.S. Army, rather than U.S. Air Force, jargon.