Clarification of dynamips behavior regarding tap interfaces

[blackbit42]

Let's assume this configuration:

dynamips \
        -i R1 \
        -X \
        -T 1024 \
        --idle-pc=0x6062dbb8 \
        -p 0:C7200-IO-FE \
        -s 0:0:tap:tap1 \
        -p 1:PA-FE-TX \
        -s 1:0:tap:tap3 \
        c7200-adventerprisek9-mz.152-4.M11.image

In my observation, this is what happens in regard to tap3 (we'll ignore tap1):
If the device does not exist on the host OS level at startup of dynamips, dynamips will create it (assuming sufficient permissions of the user account starting dynamips) and destroy the device when dynamips is being shut down.
If the device does exist on the host OS level at startup of dynamips, it'll be used as is and not destroyed when dynamips is being shut down.

That behavior is perfectly acceptable as far as I am concerned, though I did not find a description of the behavior in the documentation and want to make sure this behavior can be assumed to be consistent.