The declaration section contains declarations or definitions  of
  constants,  labels,  user-defined  data  types,  variables,  and
  user-defined  functions  and  procedures.   In  addition,   only
  modules  can  contain  initialization and finalization sections.
  Each appears in a subsection introduced by a VSI Pascal reserved
  word.

  These sections appear after the header and before the executable
  section  (if  any).   The TO BEGIN DO and TO END DO sections can
  appear only in modules and can appear only once within a module.

  The  remaining  sections  can  appear  in   programs,   modules,
  functions,  or procedures; they can appear more than once and in
  any order in a single declaration section.  If you use one  kind
  of  section  more than once in a declaration section, be sure to
  declare types, variables, and constants before you use  them  in
  subsequent sections.

  If you want to apply the HIDDEN attribute to all of the data  in
  a  declaration  section,  place the HIDDEN attribute immediately
  preceding the section header, as follows:

     [HIDDEN] CONST
        Pi = 3.14
           .
           .
           .