As implicit conditions for publishing in The Astrophysical Journal and The Astronomical Journal, authors are expected to adhere to basic standards of professional ethics and conduct that are common across all areas of scholarly publishing. In the publication agreement authors warrant that their work is original and has not been published elsewhere. All parties are also expected to conform to common standards of professional respect and civility. Fortunately, in astronomy publishing these standards are upheld in the overwhelming majority of instances. However, misunderstandings and lapses in professional conduct do occur, including instances (or accusations) of plagiarism, inadequate attribution, conflicts of interest, or personally abusive behavior toward referees, authors, editors, or journal staff members. This document summarizes the expected standards of professional and ethical conduct, with specific application to publication in the AAS Journals.