The Optional Application Field Reference, One Row per Upload and Link

This guide covers the optional boxes on an online job application: the cover letter upload, the "additional attachments" slot, the portfolio, GitHub and website link fields, and the "additional information" text box. It is for anyone with a form open right now who needs to decide, field by field, what to put in, what to leave blank, and what each choice tells the screener. Find the row for the field in front of you, apply it, and move on.

The optional slot table: one row per field

Each optional slot is read for one thing, and the right fill is the one artifact that proves that thing. A generic, broken, or duplicated entry usually sends a worse signal than a blank.

The detail for each row is further down. Two parts of this are unsettled, and I flag them where they come up. No primary source shows how often screeners open link fields, and no ATS vendor publishes a character limit for the free-text box. An ATS (applicant tracking system) is the software the employer uses to host the form and store what you submit.

Fill, filler, or blank: how to decide any optional slot

Fill an optional slot when you have a specific artifact you have checked. Leave it blank when all you have is generic filler. Treat any slot the posting names as required. The middle option, filling a slot just so it isn't empty, is the one that hurts candidates.

The payoff is lopsided. In Resume Genius's survey of 625 US hiring managers, 72% said they expect a cover letter even when the posting lists it as optional. In TopResume's survey of 600 US hiring managers, 19.6% said they would reject a candidate with an AI-generated resume or cover letter. Taken together, a blank letter disappoints some readers, a generic letter actively loses some, and only a tailored letter works for both groups.

The same logic applies to every other slot. A blank GitHub field on a backend role reads as a gap. A GitHub link to forty undocumented repositories reads as no curation. The question is never "is there something I could put here". It is "does what I'd put here prove something the resume can't".

The top half of that matrix takes time: a letter with a company-specific claim, a link that lands on the right piece. Spend that time on roles you actually fit. Refolk scores how well your history matches each posting, which tells you before you start whether a role is worth the 20 to 40 minutes a real letter takes.

Each optional slot in detail: what it proves and how it lies

Each subsection below expands one row of the table: what the slot is read for, the artifact that proves the most there, what it looks like when it misleads, and when a blank is the right answer.

Cover letter

Upload a tailored letter of one page or less, or leave the slot blank on purpose. Never upload a generic one. Whether the letter gets read depends on who is reading, and the surveys disagree sharply.

The surveys conflict because they asked different people in different ways. Resume Genius asked hiring managers and counted "always or frequently". Josh Bob's figure comes from a career coach's poll. BossMakeHer's 31% comes from recruiters. Recruiters work through volume. Hiring managers make the decision. So the letter is mostly read by whoever sits after the first screen, and you should write it for that person.

• Read for: why this employer and this role. Resume Genius found 45% of managers read the letter before the resume, and 36% spend less than 30 seconds on it, so the first paragraph has to carry the main claim.
• Strongest fill: one page or less, with at least one claim that could only be about this company. Length advice conflicts. One practitioner guide says one page and no more than 400 words, and Teal says usually 100 to 200 words. I hold the one-page ceiling and let the content decide the length within it.
• How it lies: a filled slot looks like effort, and generic AI text is the false positive. In TopResume's survey, 19.6% would reject outright, about 20% more call AI reliance a red flag, 25% call AI unacceptable for cover letters, and 33.5% say they can recognise an AI-generated resume in 20 seconds or less. The same survey found 52% accept AI for proofreading or drafting support. CV Genius surveyed 625 managers and reported that 57% are far less likely to hire an applicant who used AI. The line the data draws is between assisted and generic, not between AI and no AI.
• Blank is right when: you cannot produce one specific claim about the employer, or the fit is weak enough that a letter won't change the outcome.

Writing that company-specific claim from scratch for every posting is the part people skip. Refolk drafts each letter from your own work history against the specific posting, so you start from a draft that is already about this employer, not a template you have to de-genericise.

Additional attachments

Use the "additional attachments" slot only for something the posting requested, or something that proves more than the resume can, and attach it with a cover sheet. In Greenhouse, this slot is a custom question the employer added with the answer type "Attachment", so its presence means someone chose to ask.

The common contents are writing samples, reference lists, and transcripts. Only writing samples have codified rules, and nearly all of those come from law-school career offices:

• WashU Law: typically 8 to 10 pages. Get supervisor approval and redact. Describe any redactions on the cover sheet, and mark cut sections "[Intentionally Deleted]".
• Southern University Law Center: 7 to 10 pages (some employers ask for 5, and in rare instances 12). Use fictitious names rather than blacking out information.
• Indiana: a 5 to 10 page document is ideal.
• Lateral Link, for lateral associates: most firms want 8 to 15 pages.
• Georgetown Law: warns against a sample that abruptly ends on the tenth page.

Because these rules are explicit, breaking one reads as failing a judgment test, not as missing effort. A University of San Francisco career guide quotes a writing consultant saying that applicants who skip redaction are "often rejected on the basis of the poor judgment displayed."

Outside law, writing-sample rules and transcript conventions are not established in any source I could find. If a non-law posting asks for a sample, ask the recruiter for a page range. Failing that, borrow the law-school defaults: short, with permission, redacted, and with a cover sheet. For references, UK public-sector guidance from Derbyshire County Council says at least one referee should be work-related and you should state your relationship to each referee.

Leave the slot blank when nothing was requested and nothing you have proves more than the resume already does.

Writing sample of [Your Name]
Submitted for [Role Title] at [Employer]

This is a [brief / memo / report] I wrote in [month and year] as [your role] at [organisation]. I was the sole author; edits from my supervisor were limited to [describe].

Permission. [Supervisor or organisation] has given me permission to use this document as a writing sample.

Redactions. Client and party names are replaced with fictitious names. Confidential details in [sections] have been removed.

Cuts. The full document is [n] pages. To keep this sample to [n] pages I removed [describe sections]. Each cut is marked [Intentionally Deleted] in the text.

Portfolio link

Fill the portfolio field whenever the role judges finished work, and make the link land on your best piece. The screener is reading for quality, fast, and every click between the field and the work costs you.

• Strongest fill: a URL that opens directly on, or leads with, your strongest piece, and loads in a logged-out browser.
• How it lies: a page of bare links that hides the best piece among the rest, or a cloud folder that asks for access. Some Workday employers let you link a cloud URL in the websites section instead of uploading. McGill does this because all files together there cannot exceed 5MB. That shifts the work onto a click, and whether link fields are clickable for screeners is not established publicly.
• Blank is right when: the role doesn't judge visible work, or everything you could link is weaker than the resume.

GitHub link

Fill the GitHub field when it exists and your profile shows curated work. Leave it empty on roles that don't evaluate code. Lever adds link fields per employer account rather than by default, so a GitHub field on a form is usually a field someone chose to ask.

How often screeners open GitHub links is not established by any primary source. A "71%" figure attributed to a Stack Overflow survey has no primary source. "76% of technical recruiters screen GitHub profiles before outreach", attributed to LinkedIn Talent Solutions, is unverified. An "87%" figure is unattributed. No breakdown by role family exists. Against all of these, one interviewer on a Blind thread wrote: "Interviewed over 150 people. Never looked at any GitHub." So assume the link may or may not be opened, and that if it is, curation decides what happens next.

• Strongest fill: pinned repositories related to the role, each with a README. A job-board guide puts it plainly: forty poorly documented repositories is less impressive than six well-maintained ones.
• How it lies: a bare profile with plenty of repositories and no curation looks like activity but reads as noise.
• Blank is right when: you have no pinned public work related to the role. One caution from a Lever how-to: on a role that clearly wants a link, an empty field reads as a gap. In that case, curate before you apply.

Personal website and other link fields

Use the "website" or "other" field for one page the resume can't hold, and never repeat a URL that is already in another field. On Lever forms, the word "URL" is added to each link name on the applicant form, so a field the employer called "Portfolio" appears to you as "Portfolio URL".

Lever's API stores link answers as a set of URLs for sites such as GitHub, Twitter, LinkedIn, and Dribbble, so each field is captured as a separate entry. That is why duplication shows. One documented autofill bug wrote the same site into two fields: "Portfolio and Other website both received the profile website". Leave the field blank when the only thing you could put there is a link you've already given.

Additional information box

Leave the additional information box blank unless you have a fact that helps the recruiter say yes. If you do, write it in two to four plain sentences. The test: does this give the recruiter information they don't already have, and would it help them say yes?

Uses that pass the test:

• An employment gap explained, for example as travel or family reasons (Derbyshire County Council's guidance)
• A driving licence or languages
• Relocation plans and availability
• The name of whoever referred you
• An accommodation request

Uses that fail: salary, which should be raised only if the hiring manager asked. No recruiter survey covers pasted resumes or complaints about past employers, so I can't cite evidence on either. Both fail the test anyway: the first repeats what they already have, and the second doesn't help anyone say yes.

The sources disagree on the default. Jobrizzer says most of the time, leave it blank. A Lever how-to says to use the box as a short cover letter when it stands in for one. They fit together like this: if the form has a cover letter upload, the box is for logistics. If it has no letter slot, the box is the letter, and you write a compressed version. Lever stores the answer as "Additional information from the candidate". Character limits are not published for any vendor, so keep to four sentences and you will fit whatever limit applies.

I am relocating to [city] in [month] and can start [date or notice period].
[Name], [their role] at [Employer], suggested I apply for this role.
The gap from [month] to [month] was for [travel / family reasons], and I am fully available now.
I hold a full driving licence and speak [language] at a professional level.

Which ATS runs the form, and what its upload limits are

The URL usually tells you: look for greenhouse, lever, or myworkdayjobs. The vendor sets the accepted file types. Size limits sometimes come from the vendor and, on Workday, from each employer.

What each row means on the form:

• Greenhouse: the upload ceiling is generous, but the parse limit is what matters. See the next section.
• Lever: Resume, Full Name, Email, Phone, Current Location, and Current company appear on every form and cannot be deleted. Everything else was a choice: link fields are added per account, and clicking "+ Additional Information" adds the free-text question.
• Workable: a 5MB resume limit and a separate 20MB limit for custom-question uploads.
• Workday: limits vary by employer. North Carolina's state site says "Attachments larger than 5 megabytes will not attach." The University of Miami allows up to five documents at 5MB each. At McGill, all files together cannot exceed 5MB. Assume you cannot edit a Workday application after you submit it.

Which system you're on also predicts which slots you'll see. In Refolk's index of professional profiles, recruiters and talent acquisition partners who list an ATS as a skill split like this:

Read it this way. Workday-tagged recruiters cluster at enterprise, healthcare, and university employers, where the employer sets per-file caps and you may get one upload slot or five. Greenhouse-tagged recruiters cluster at tech firms, and so do GitHub fields. It is an inference, but a reasonable one: when a GitHub field appears, the employer chose to ask for it. The US to UK gap on Greenhouse is 26x, so outside the US, don't assume which system you're on. Check the URL. Two limits on this data: these are self-reported skill tags, not ATS market share, and the title filter let in some noise, including one Pilates Instructor.

What happens to an upload after you click submit

An upload passes through several layers, and getting past the first layer (accepted) doesn't mean getting past the later ones (parsed, opened, read). Candidates treat the confirmation email as proof of all of them. It proves only the first.

In Greenhouse, the resume, cover letter, take-home test, and other attachments all sit in the candidate's Details tab under All Attachments. When a resume fails to parse, Greenhouse's own wording is that the file was attached but its information could not be placed into candidate fields. Lever usually builds its parsed resume from an attached PDF or Word document, or from an online profile such as LinkedIn, GitHub, or AngelList. Whether link fields or optional attachments can be keyword-searched by the recruiter is not established in the vendor documentation I could retrieve. Assume they can't be, and put anything a searcher needs to find in the resume itself.

The 2.5 MB figure comes from secondary sources citing Greenhouse documentation, not from the Greenhouse page I retrieved. That's why I treat it as a ceiling to stay under, not a line to test.

How optional slots go wrong: failure modes and false positives

Most of these failures look like success from the candidate's side: the form accepted it, the field is filled, the confirmation arrived. Each one below has a check that catches it before you submit.

1. Oversized upload. The file submits, the confirmation arrives, and the resume never parses. This looks like a successful upload. Check: every file is under 2.5 MB.
2. Over-cut writing sample. You cut the last pages of a 12-page sample to hit 10, and it ends mid-argument. Georgetown warns specifically against a sample that abruptly ends on the tenth page. Check: every cut is marked on the cover sheet and in the text.
3. Unredacted sample. A sample used without supervisor permission or redaction signals poor judgment, and in law that is a known reason for rejection. Check: the cover sheet states that permission was obtained.
4. Bare GitHub profile. Many repositories, no curation, nothing pinned. This looks like a strong profile. Check: pinned repositories, each with a README.
5. One URL pasted into every link field. Autofill or haste puts the same site in Portfolio and Other website. Check: read each link field back before submitting.
6. AI filler in the letter. The slot is filled, so it feels done. 19.6% of managers would reject outright, and about 20% more call AI reliance a red flag. Check: the letter contains at least one company-specific claim.
7. Planning around survey percentages. The "71% check GitHub" figure has no primary source, and neither do the 77% and 35% cover letter figures. Check: rely only on surveys with a named sample.
8. Using the Workday websites section as a workaround. Linking an oversized file instead of uploading it makes the reader click through, and whether those links are clickable for screeners is not established. Check: compress the file and upload it first, and fall back to a link only if the employer's cap leaves no other option.

The slot-by-slot procedure

Run these steps in order on any application form. The whole pass takes about 10 minutes plus whatever writing the letter and samples need. Step 1 matters most on Workday, where one employer allows a single attachment and another allows five files of 5 MB each.

Before you submit, and keeping this reference current

Go through the checklist below on every form. Then re-check the vendor limits whenever a form behaves unexpectedly, because limits are set in help pages and employer settings that can change without notice.

To keep this reference current, re-check things in this order:

• File limits: the Greenhouse supported-formats article, Workable's application file types page, and, for Workday, the employer's own HR FAQ, since Workday limits are set per employer.
• Link field behaviour: Lever's "Configuring your Lever Application Form" help page and its Postings API documentation on GitHub show which fields are fixed and which the employer added.
• Survey figures: before repeating any percentage about cover letters or link-opening, confirm there is a named survey with a stated sample. The Resume Genius and TopResume surveys meet that bar. The circulating GitHub figures do not.

When a new optional slot appears that isn't in the table, apply the same four questions: what it is read for, what artifact proves the most there, how it lies when filled badly, and when a blank is the honest answer.