The Library of Congress is nixing the term "illegal alien" from its international subject headings in response to student activists at Dartmouth College who complained that the wording is dehumanizing.

An alliance of students at the Ivy League institution who advocate for immigration reform first sent a petition to the Library of Congress in 2014 urging staff to instead use the term "undocumented" to describe those in the United States illegally, The Dartmouth reported.

The Library of Congress has announced that it will use "unauthorized immigration" and "noncitizen" to replace "illegal aliens" in its bibliographical records. The Library of Congress Subject Headings is the most commonly used library indexing tool in the world.

The Dartmouth Coalition for Immigration Reform, Equality and DREAMers, or CoFIRED, worked with library associations across the U.S. to push for the changes.

Dennise Hernandez, co-director of CoFIRED, said in a statement released Tuesday that "referring to immigrants as ‘illegal’ is an offensive, dehumanizing term and … there is no excuse to continue using it." Hernandez demanded that politicians and media outlets stop using the phrase "illegal aliens."

Other activists argued that there is no such thing as an "illegal person."

Officials at the Library of Congress in 2014 initially rejected CoFIRED’s petition advocating to replace "illegal alien" with "undocumented immigrant," arguing then that the terms are not synonymous.

Library staff ultimately determined that the word "aliens" is often misunderstood and that the phrase "illegal aliens" has become pejorative.

"Illegal aliens is a dehumanizing, racially charged term," Oscar Cornejo, co-founder of CoFIRED, told Fox News. "It’s about changing how we talk about things. The word alien makes undocumented people seem far removed … extraterrestrial."

"Illegal alien" is still an official government term used to describe immigrants who are in the country illegally.

In October 2015, Rep. Joaquin Castro (D., Texas) introduced legislation that would eliminate the term from federal law. The bill has yet to advance.

The movement to drop the term gained momentum in 2013 after the Associated Press announced it would no longer use "illegal" or "illegal immigrant" to describe individuals.