Be conservative in what you send, liberal in what you accept.
npx skills add https://github.com/DnfJeff/Expand-YOYR-MIND --skill postelCopy and paste this command into Claude Code to install the skill
Educational philosophy — learn by building inspectable things
Protocol names ARE K-lines.
Rules persuade. Structure IS argument. Design consciously.
Objects clone from prototypes, not instances from classes
Survive first. Be correct later.
Survive first. Be correct later.
| name | postel |
| description | Be conservative in what you send, liberal in what you accept. |
| license | MIT |
| tier | 1 |
| allowed-tools | ["read_file","write_file"] |
| related | ["yaml-jazz","robust-first","empathic-expressions","empathic-templates","honest-forget","coherence-engine","sniffable-python"] |
| tags | ["moollm","robustness","interpretation","protocol","rfc"] |
"Be conservative in what you send, liberal in what you accept." — Jon Postel, RFC 761 (1980)
POSTEL is how MOOLLM handles ambiguity, errors, and incomplete instructions:
Instead of failing, find the best possible interpretation that:
Also known as:
When faced with ambiguity:
1. GATHER context — what do we know?
2. INFER intent — what did they probably mean?
3. PROPOSE interpretation — state your understanding
4. ACT constructively — do the reasonable thing
5. REPORT uncertainty — flag what you assumed
Input: "delete the old files"
POSTEL Response:
I interpret "old files" as files not modified in 30+ days.
Found 12 candidates in ./temp/
Before deleting, I'll:
1. List them for your review
2. Move to trash (not permanent delete)
3. Wait for confirmation
Proceed? [Y/n]
Input: User config missing email field
POSTEL Response:
user:
name: Alice
email: null # POSTEL: not provided, leaving empty
# Will prompt if needed for notifications
Input: "Make it faster AND more thorough"
POSTEL Response:
These goals tension against each other.
Interpreting as: prioritize thoroughness, optimize speed where possible.
Alternative interpretations:
- Speed-first with configurable depth
- Parallel processing for both
Which approach fits your needs?
"Be conservative in what you send, liberal in what you accept."
This was written for TCP implementations, but applies universally:
"Interpret others' words in the best possible light."
Don't assume incompetence. Don't assume malice. Assume the human had good reasons you might not see.
Always show your work:
Use POSTEL when:
❌ Literal failure — "Field X is required" (without trying to infer)
❌ Silent assumption — Acting on interpretation without stating it
❌ Overcorrection — Changing user intent to match your preferences
❌ Analysis paralysis — Asking 20 clarifying questions instead of proposing
Jon Postel was one of the founding architects of the Internet. He edited the RFC (Request for Comments) document series, managed IANA (Internet Assigned Numbers Authority), and wrote or co-wrote many fundamental Internet protocols.
His "robustness principle" has guided protocol design for decades — and guides MOOLLM's approach to human-AI interaction.
POSTEL
Invoke when: Facing ambiguity. Choosing constructive action over failure.
Related symbols: CHARITY, ROBUST-FIRST
See: PROTOCOLS.yml