Where blindness is real, the responsibility usually sits with the writer
Competitions are the clearest case, because the requirement is stated and enforced. The Academy Nicholl Fellowships in Screenwriting put it on the entrant. The entrant is responsible for ensuring that no name, address, phone number, or other identifying information appears on the title page, or on any other page of the script.2
Read that sentence for what it does not say. It does not say the competition will remove anything. It does not say a stray header will be overlooked. The obligation is the writer's, and the consequence is theirs.
The four places identity survives a careful edit
The first is the page itself. Headers, footers, a running head carrying the author's surname, and a title page updated everywhere except on the second copy all belong to this category.
The second is the file rather than the page. Document properties carry an author name, a company, and a list of previous authors, and none of that is visible when the document is read or printed. Tracked changes and comments carry initials. A file named with the author's surname announces it before the file is opened.
The third is the prose. Self-citation written as our earlier work does the same job as a signature. So does an acknowledgment, a funding statement naming a specific grant, and a methods section naming an institution's own facility.
The fourth is the surrounding material. A cover letter, a submission portal profile, and a preprint posted under the author's name can all undo the work done inside the manuscript.
What an editor can check, and what only the author knows
Three of those four are checkable by someone who does not know the field, and the fourth is not checkable by anyone but the author.
An editor can search a manuscript for every proper noun and list them. An editor can report every first-person reference to prior work. An editor can inspect document properties, comments, and tracked-changes attribution, and say what they contain. Each of those produces a list rather than an opinion, and each is the kind of mechanical completeness check Editors Canada places inside copy editing, which covers checking for missing information and resolving inconsistencies.3
What an editor cannot judge is which of the identifying details a specialist reader would recognize anyway. A method used by three laboratories in the world identifies its author to anyone in that field, and no amount of name removal changes it. That assessment belongs to the author.
Confidentiality runs the other way too
The obligation is not only the author's. The International Committee of Medical Journal Editors states that manuscripts submitted to journals are privileged communications and the authors' private, confidential property.4 That is the standard the recipients are held to, and it is a reasonable one to expect from anyone else who handles the file.
An editor is one of those people. Everything a client sends to EditFast is treated in confidence, including unpublished manuscripts, submission correspondence, and data. Nothing is retained beyond the work, and nothing is shown to anyone outside it. A file that has to arrive anonymized should leave the same way.
The order that saves the week
Read the recipient's own instructions first and find out whether the review is anonymized at all. Where it is not, the anonymization work is unnecessary and the time is better spent on the conformance check the submission actually requires.
Where it is, do the file-level work last, after every other edit is finished. Document properties are rewritten every time a file is saved by a new person, so a manuscript cleaned in the morning and edited in the afternoon is no longer clean.
EditFast proofreads against a recipient's published requirements where a client supplies them, and reports what does not conform, including what sits in the file rather than on the page. We work on journal articles and on screenplays and scripts. Whether a manuscript is ready on its merits stays with the author.