[erlang-questions] Hot code upgrade

[Arun]

Hi,

     I am trying to upgrade my application using rebar3 hot code upgrade 
feature from version 0.0.1 to 0.0.2 and my application consists of 
around 20 modules, the difference between current version and the new 
version is that one new module got added and one existing module code 
has been modified. My doubt is that, in the appup file we have to give 
list of instructions to upgrade and downgrade software between different 
versions, is it mandatory that all 20 modules has to be mentioned in the 
instructions or the modules which are added or modified only need to be 
mentioned. ?

Can anybody assist me on this

regards,
Arun