  The problem of connecting the operator parameters that label the same
self-adjoint extension of a given symmetric operator, respectively, within the
'absolute' von Neumann extension scheme and the 'relative'
boundary-triplet-induced extension scheme (i.e., a la
Kre\u{i}n-Vi\v{s}ik-Birman) is discussed, and quantitative connections between
the two parameters are established in the limit of deficiency spaces at complex
spectral points converging to the deficiency space at a real spectral point.
