[Nek5000-users] set boundary condition on spectral element

Hello, I have a question about setting boundary condition on spectral element mesh when I am not sure that on the boundary condition I have spectral mesh or not?! like pipe with some extension in inlet/outlet that boundary condition is located at the beginning of pipe but the mesh started from extension. What I thought was using normal surface to specify spectral boundary condition there! Is that right?! my question is to how set the boundary condition on spectral element? Thank you, Ami