Initial values of shocks stderr

Hi Prof. Pfeifer and to all,
I have a theoretical question.
What Rules are there for setting initial values of shocks stderr ​at Bayesian estimation in Dynare?
Thank you,

What do you mean with

Usually people start at the prior mean or mode.

Hi Prof. Pfeifer,
I have a theoretical question.
How to set the correct prior mean ​of stderr at Bayesian estimation for
some of the shocks, the earlier literature give less guidance.
Thank you,

Please see

Thanks for your prompt reply, jpfeifer!