A group of Republicans in the House of Representatives is calling for the public release of a classified four-page memo they say shows a shocking misuse of power by people at the highest levels of the FBI and Department of Justice in relation to Trump campaign surveillance.

Those advocating for the release of the memo, written by California Republican Representative Devin Nunes, have pushed the trending Twitter hashtag #releasethememo for the cause. In addition to members of Congress, some of the greatest advocates for the document’s release have been Fox News anchor Sean Hannity and the president’s son, Donald Trump Jr.

Calls for the memo’s release have been loud and public, but the contents and circumstances surrounding the memo have remained surprisingly secretive. Here’s what we know:

The memo reportedly targets Deputy Attorney General Rod Rosenstein’s decision to approve an application extending surveillance on Carter Page, a former associate on President Donald Trump’s election campaignThe memo’s main gripe is that officials within the FBI and DOJ did not inform the intelligence court judge from whom they sought approval of the warrant that some of the information used to justify it came from the now infamous dossier that alleged years of collusion between Trump and the Kremlin. But surveillance warrants are seldom approved on the basis of just a single piece of information.

Nunes and Republicans steadfastly argue that the memo is based on the facts of what happened, but Democrats on the House Intelligence Committee have contended that the document is made up of “a misleading set of talking points attacking the FBI.” Additionally, Democrats have argued that Republicans composed the memo and are seeking its release as a means to discredit special counsel Robert Mueller’s investigation into the Trump campaign’s suspected Russian collusion.

Representative Devin Nunes is at the center of one of Washington’s biggest battles this week.

As of now, the memo has been seen by members of the House of Representative after the House Intelligence Committee voted to grant all members of the House access to the memo. But only a small number of Congress members have the security clearance to view the classified materials on which the memo is based. Further, Nunes rejected a request from Senate Intelligence Committee Chairman Richard Burr (R-N.C.) to view the document himself. Officials at the DOJ, FBI and White House have also not seen the memo. Even the president himself has not seen the memo, according to White House deputy press secretary Raj Shah.

The question now becomes whether the memo will ever be released publicly. The DOJ warned Nunes that releasing the memo to the public would be “extremely reckless,” but that won’t stop Nunes if he wants to make the document public.

The process goes as follows: If a majority of members on the House Intelligence Committee vote to make the memo public, Trump then has five days to block the memo’s release. If those five days pass with no White House action, the information will be released publicly.