Symptom
The same group of fields travels together everywhere — (street, city, zip), (start, end), (firstName, lastName) — appearing as parameters, fields, or method args.
Goal
The clump becomes a value object with its own name and its own behavior.
Smellier version
function send(name, email, street, city, zip) {
// ...
}class Address { /* street, city, zip */ }
function send(name, email, address) {
// ...
}Savings
Operations on the clump (formatting, validation, equality) live with it; method signatures shrink.
Note
Adding or removing a field of the clump means touching every site; the clump's identity is invisible.