In this section of the Matrix Fields page, the third bullet is incomplete:
Default to an empty array (this fallback ensures)
This section (further up the page) also doesn't flow well—the relationship between the two clauses is not established:
For example, the first new block that is added to the form could have an “ID” of new:1, so its type input name would end up looking like this (ignoring for a moment any namespace tags)…
In this section of the Matrix Fields page, the third bullet is incomplete:
This section (further up the page) also doesn't flow well—the relationship between the two clauses is not established: