Where to start

Everything that should come out before it leaves you: the location in a photo, the author's name, the tracked changes nobody meant to send, the key in a config file.

Look before you open. What is inside it, what it would run, whether the email really came from who it says, and where that link actually goes.

Properly, so the words underneath are gone rather than covered over, and so the faces and the plates are not recoverable from the file.

A hash ties a document to its exact bytes. A chain of custody ties it to the hands it passed through. A certificate says who checked it and when.

Work out the date, show the counting, and keep the record that shows you met it.

What your browser gives away, what is in the email, what is in the link, and how to get yourself off the lists.

Making them, checking them, carrying them between machines, and keeping a copy you can still read in ten years.

Merge them, number them, index them, stamp them, and list what was held back and why.

The hour when there is no network, no account and nobody to ask. Arithmetic and bookkeeping that run on a device with nothing behind them.

The ordinary office work, with nothing to sign up for and nothing leaving the machine.

What is on the document besides the part they asked for, who needs which part of it, and what happens to a copy once it has left you.

The location in a photo, the author in a document, the text under a redaction and the dots a printer adds: what each format carries, and where.

A face, a voice, a writing style, a front door on a running route, a name in a spreadsheet: what identifies a person once the obvious part is gone.

Hashes, signatures, saved revisions and edit histories: what each can show about a file, and the point where each stops being able to tell.

HEIC, .msg, winmail.dat, a .docx without Word, a CSV in one column, a zip Windows refuses, and pages that move or shrink on the way to the printer.

Passwords that hold, the kind of PDF and zip password that protects nothing, signatures and what each proves, and sending a file without a server keeping it.

Checking a PDF, an extension or a QR code before trusting it, and reading captures, DNS logs, connection logs and USB history for what they show.

Averages, charts, samples, dates, units, coordinates and timestamps: the arithmetic that looks settled and has two answers, and how to tell which one you have.

Slings, fall arrest clearance, levelling, stairs, tile orders, cordons, triage and rotas: the working that has to be right before anybody relies on it.

When a piece of writing is doubted: what a detector's score does and does not mean, what counts as evidence of how it was written, and how to keep that evidence yourself.

Chronologies, call records, association charts, reconstruction arithmetic, custody clocks and bundles: the record somebody will read closely later.

Merging, compressing and converting PDFs, reading text out of a scan, transcribing, shrinking a photo, making a CV or an EPUB, all in the tab.

The office suite, the photo editor, the PDF service and the planner, each set against the product people leave, with what does not come across.