Plain English
Custom instructions
Standing instructions you give an assistant once, so it follows them in every chat.
A setting where you tell an assistant who you are, how you like answers and what rules to follow, so you don’t repeat them in every chat. Custom assistants and projects take the idea further by adding reference files.
Why it matters
Good instructions make answers more consistent and more like your business. Keep them short, and update them when your prices, policies or tone change.
At work
“We’re a family plumbing firm. Write in plain US English, keep emails under 120 words and never promise a same-day visit.”
Think of it like your usual order at the local café: they know how you take it without being told each time.
Related terms
Where it appears