recovery_target_time format explanation should be clarified when using UTC zone

The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/18/index.html
Description:

We've been hitting a bug with PITR when specifying a recovery_target_time
with an ISO 8601 format and UTC zone indicated with a trailing `Z`.

We get an error like this

```
"msg":"waiting for server to start....2025-10-28 16:40:20.324 UTC [38]
LOG: invalid value for parameter \"recovery_target_time\": \"2025-10-28
16:34:15.000000Z\"",
```

The documentation states

> The value of this parameter is a time stamp in the same format accepted by
the timestamp with time zone data type, except that you cannot use a time
zone abbreviation
> [-snip-]
> Preferred style is to use a numeric offset from UTC, or you can write a
full time zone name, e.g., Europe/Helsinki not EEST.

That `Z`, if it's an abbreviation, would be an abbreviation for Zulu, I
presume? I tried to use `Zulu` and not just `z` but still had the same
`invalid value` error.

For timestamps in UTC zone, I think the only supported format would be
numeric offset, right? With `+00` instead of `Z`.
I think that the documentation should clarify this explicitly.
Unless there is a full name for the UTC zone which I'm unaware of...

Thanks