Case lab: build, repair and round-trip clusters

Hands on: the grammar

Time to practise the grammar. Three drills from the lab, each with a WHO answer to check against.

Attach the extensions

Drill one. You are given a stem code and two extension codes. Build one cluster, stem first, joined with ampersands. WHO's example: acute pyelonephritis, left, Escherichia coli. In the lab this is the challenge attach extension codes to a stem.

• GB51 · Stem code
• XK8G · Laterality
• XN6P4 · Infectious agent

Repair a broken cluster

Drill two. A string came out of an integration with the extension first. Extension codes can never come first in a cluster, so the repair is the same two codes with the stem first. In the lab, this is repair a broken cluster.

Two stems, each with its own

Drill three. Two conditions, each with its own detail. Join them in one string, each stem followed by its own extensions, with a slash between the groups. In the lab, this is two conditions in one cluster. And remember: only when the documentation links them.

• Given · Two conditions · Two documented conditions, each with its own detail.
• Task · One string · Join them, each stem followed by its own extensions.
• Rule · / · A slash separates the first stem's group from the next stem.

Check yourself

Pause and think. Two documented conditions each have their own detail. How do you build one string? The answer: Each stem followed by its own extensions, with a slash between the groups. Each stem is followed by its own extensions, and a slash separates the groups. Only do this when the documentation links the conditions.

• All extensions first, then both stems
• Ampersands everywhere
• One stem, with all extensions after it
• Each stem followed by its own extensions, with a slash between the groups

Keep these in mind

Stem first, extensions with ampersands. Extensions can never be first. And a slash starts the next stem's group.

• Stem first, extensions with ampersands
• Extensions can never be first
• A slash starts the next stem's group