Incrementally Updated Backups: Docs Clarification

I'm about to begin playing with incrementally updated backups for a
warm standby scenario, but I need some help understanding this
paragraph in postgres terms. From 23.4.5 in the 8.2.3 docs:

"If we take a backup of the standby server's files while it is
following logs shipped from the primary, we will be able to reload
that data and restart the standby's recovery process from the last
restart point. We no longer need to keep WAL files from before the
restart point. If we need to recover, it will be faster to recover
from the incrementally updated backup than from the original base
backup."

I'm specifically confused about the meaning of the following phrases:

"backup of the standby server's files" - Which files?

"reload that data" - What does this mean in postgres terms?

"last restart point" - What is this? Wouldn't it be able to restart
from the last recovered file, which would presumably occur later than
the last restart point?

Does this mean make a filesystem backup of the standby server's data
directory while it's stopped, and then start it again with that data
and the restricted set of WAL files needed to continue recovery? I'd
like to see the language here converted to words that have more
meaning in the context of postgres. I'd be happy to attempt a
revision of this section once I'm able to complete an incrementally
updated backup successfully.

Here's how I envision it playing out in practice:

1. stop standby postgres server
2. [optional] preserve data directory, remove unnecessary WAL files
3. restart standby server

Is that all there is to it?

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Thomas F. O'Connell

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