Register an account called 'Acme Marketing' on English Wikipedia, and the name alone can end the account before it edits a single page. Usernames get reviewed on their own terms, separate from anything the account later writes, under a policy — WP:U — that treats certain names as a problem no edit can fix.
Two different checks do the work, and they rarely overlap. A short blacklist of patterns rejects a handful of usernames the instant someone tries to register them: names that impersonate Wikipedia's own interface, strings reserved for bots, a handful of slurs filtered everywhere on the site. Most problem names clear that check without friction, because software has no way to tell a marketing agency's name from a surname. 'Acme' passes. What catches the rest is a volunteer.
That volunteer works a noticeboard called Usernames for Administrator Attention, reading the New users log the way a copy desk reads wire copy — fast, and for one thing. A name ending in 'Marketing,' 'Media,' 'Consulting' or 'SEO,' or matching a company's name outright, gets flagged there, often within hours of the account's first appearance and sometimes before its first edit is even saved. An administrator who agrees applies a soft block: the account stops being usable under that name, but nothing about it is punished. Its contributions stand, its block log stays clean, and a one-line notice invites the owner to pick a personal name and keep editing.
A username that is the name of a company, group or organization is not permitted, because it implies that the account is controlled by more than one person and advertises the organization regardless of intent.
A related rule, WP:ROLE, catches the account a department sets up for whoever is on shift — 'Acme Communications,' logged into by three different people across one product launch. Wikipedia's block log, talk-page history and edit-warring rules all assume a single person behind a single account; a role account breaks that assumption even when every edit it makes is accurate and disclosed. The editor who names an account after their employer is usually aiming for candor. Paid-contribution disclosure, required under WP:PAID, already asks for exactly that: a declared employer or client, stated plainly. Policy delivers it through a sentence on a named person's user page, through an account one identifiable editor controls — never through a login that does the declaring on its own.
The fix costs little, and works best applied before the account exists: pick a personal handle, put the employer or client in a disclosed statement on the user page instead of in the login, and let one identifiable person answer for every edit the account makes. A soft block costs a day and a rename. A pattern of accounts named after the same company costs that company credibility at every deletion discussion it shows up to afterward.
