Semicolons ;

The semicolon as a punctuation mark has fallen out of fashion in recent years. In an earlier era, it was sometimes used to achieve a stronger pause than a comma, but commas and dashes have largely overtaken that function.

However, 2 remaining uses of the semicolon are worth preserving:

separating items in a complex list within a sentence
separating independent clauses in a complex sentence without a conjunction.

Serial list items

Separate complex list items in a sentence with semicolons, but prefer a bulleted list

If you have a reasonably complex serial list within a sentence, you can use semicolons to separate each item. Put a colon after the introductory phrase or clause.

Project delivery agreements can involve: RedDev as the land owner; RedDev and the land owner (reverse project delivery agreement); and RedDev and the delivery organisation (developer).

But it will often be clearer to use a vertical list (usually bulleted) instead. In this case, don’t add semicolons to the end of each point because the bullets and the line breaks add alternative punctuation.

Project delivery agreements can involve:

RedDev as the land owner
RedDev and the land owner (reverse project delivery agreement)
RedDev and the delivery organisation (developer).

Independent clauses

Divide independent clauses that aren’t joined by a conjunction

If you have 2 independent clauses that are related but need to remain distinct, you can separate them with a semicolon.

We examined their reports; we considered them incomplete.

It's more common to use a comma and a conjunction instead of a semicolon in these cases.

We examined their reports, but we considered them incomplete.

You can even break this into 2 sentences.

We examined their reports. We considered them incomplete.

Just don't separate the 2 clauses with a comma alone. This is known as a comma splice and should be avoided.

We examined their reports, we considered them incomplete.