Glossary
Custom instructions
Custom instructions are standing notes you save in an AI's settings (who you are, how you want answers) so it remembers them in every new chat instead of you repeating yourself each time.
Custom instructions are the five minutes of setup that improve every conversation afterwards. Instead of starting each chat with “I run a small bakery, keep it simple, answer in English, no bullet-point spam,” you write that once in settings and it applies automatically.
Think of a regular at a bar: after a while the barista just knows: macchiato, no sugar, no small talk before nine. Custom instructions make you that regular on day one. The AI reads your notes before every new chat, like a personal system prompt layered on top of the official one.
Two practical tips. Keep them short and factual: profession, audience, tone, pet peeves. And leave out anything sensitive: these notes are sent along with every conversation, so they deserve the same caution as anything else you paste.
Where you’ll meet this
ChatGPT: Settings → Personalization → Custom instructions. Claude: Settings → Profile preferences. Gemini calls it “Saved info.” All do the same job with different names. If you don’t know what to write in them, our setup wizard builds a sensible starting set from a few questions.