The phrase "at once includes" is correct and usable in written English.
It can be used to indicate that something is included immediately or simultaneously within a certain context.
Example: "The new policy at once includes provisions for remote work and flexible hours."
Alternatives: "simultaneously encompasses" or "immediately incorporates".
A lot of things are going on at once, including a daylong film festival.
Most of them were infected with several viruses at once, including cytomegalovirus, Epstein-Barr and human herpesvirus 6.
At times, two or three gun battles raged at once, including at the outposts where the Marines had left their equipment.
Geico is running a half-dozen campaigns at once, including commercials with geckos, cavemen, a "googly eyes" character and celebrities like Charlie Daniels.
Often a claimant will sue 60 entities at once, including bankrupt manufacturers' trusts.The problem is that much of the money is going to the wrong people.
6. Trivago.com If you want to compare many hotel sites at once (including heavyweights like booking.com and hotels.com), try Trivago, an easy-to-use metasearch site.
In her piece, Ms. Donohue used a nimble touch to string together several genres at once, including Asian-themed musicals, 1980s rock and drag culture.
With so many features introduced at once, including commissioned pieces by contemporary artists, it's probably inevitable that the initial results have a somewhat hectic, hodgepodgey look.
We are being sold on the need to upgrade all parts of ourselves, all at once, including parts that we did not previously know needed upgrading.
Profoundly peripatetic, Mr. Flanagan often maintained apartments in several cities at once, including Amsterdam, Paris, London, New York (at the Chelsea Hotel) and Barcelona and periodically traveled around Europe in a Rolls-Royce pulling an Airstream trailer.
