Substring search option of module command

Using option --substring or simply -S with module avail you can search a module name or a substring in the module name from the available modules on the system. This is at times a convenient way to discover available modules of interest where there are many containing the same substring. E.g. below is an instance where I wish to search all the modules containing substring petsc. Module command will search this substring in all available modules and list the hits:

shaima0d@cdl4:~> module avail -S petsc

----------------------------------- /opt/cray/pe/modulefiles -------------------------------------------- 

cray-petsc/3.9.3.0                   cray-petsc-64/3.9.3.0                   cray-petsc-complex/3.9.3.0    
cray-petsc-complex-64/3.9.3.0        cray-petsc/3.11.2.0(default)            cray-petsc-64/3.11.2.0(default) 
cray-petsc-complex/3.11.2.0(default) cray-petsc-complex-64/3.11.2.0(default) cray-petsc/3.12.4.1 
cray-petsc-64/3.12.4.1               cray-petsc-complex/3.12.4.1             cray-petsc-complex-64/3.12.4.1