The information in this section does not pertain directly to the profile steps, but it is important to your understanding of MARS 2.0 authority control processing.
Prior to the adoption of AACR2, each work was to be cataloged under the actual name of the author.
All works written under the pseudonym, Mark Twain, were to be cataloged under the author's actual name, Samuel Langhorne Clemens. LC authority records were constructed in such a way that all Mark Twain headings would be flipped to Samuel Langhorne Clemens during authority control processing.
With the adoption of AACR2 in 1988 and its concept of bibliographic entities, works could be cataloged under the name the author chose to use.
Prior to that time, works written under the pseudonym Mark Twain could not be cataloged under that name. Now, Mark Twain is an authorized heading and books penned by Mark Twain are cataloged under that name.
LC has steadily added new authority records for bibliographic entities (or pseudonyms), and changed the 4XX See From xref under the author's actual name to 5XX See From Also xrefs.
This effort has been essentially completed and there remain few, if any, LC name authority records that contain a pseudonym as a See From field.