JAILS in FreeBSD manual - Minor ambiguity between 15.6.1.3 Creating Jails & 15.6.1.4 Upgrading

[Matthew]

Hello,
"15.6.1.4 Upgrading" in the FreeBSD manual provides a great step, by 
step way to safely update jails.  I've just installed apache in the host 
system, and now I wish to propagate it to the system wide jail skeleton, 
and www jail.

But given my limited experience with jails, I am perplexed to read in 
the 2nd last sentence of this section: "Do not forget to run mergemaster 
in each jail".
The instruction doesn't say between which steps (which one between 1 
through 6) to run mergemaster, and I'm left guessing as I'm still coming 
up to speed on jail configuration and maintenance.

Carefully reading *15.6.1.2 "Creating the Template"* it says that 
mergemaster is run in:

Step 4 - Use Mergemaster to install missing configuration files...

This follows:
Step 1 - Create a read-only directory structure for the read-only file 
system...(make installworld)
Step 2 - Prepare FreeBSD ports collection for the jails...
Step 3 - Create a skeleton for the read-write portion...

However *15.6.1.4 Upgrading* shares only step 1 (make installworld), but 
steps 2 through 6 are quite different.  I am left wondering between 
which steps in 15.6.1.4 Upgrading that I am to run mergemaster on each 
jail.  I would be very happy to get a tip.

Thank you,
Matthew