Arvit (xxx)
Based  on  the  rules  which generated  "Arvit  (Sephardic),"  "Arvit  (Sabbath)"  and  "Arvit (Sephardic   :   Sabbath),"  the   heading   needed   is   "Arvit (Reconstructionist : Sabbath)."
The "rite" qualifier, "Sephardic" or "Reconstructionist," is prescribed by  AACR2R  rule 25.22A.   The "explanatory" qualifier
"Sabbath"  is prescribed  by  rule  25.5B1  and distinguishes the Sabbath Arvit  from  other  parts  of  the  liturgy  also  called
"Arvit."  Both qualifiers are necessary  to distinguish the  work represented by  the heading from, on  the one hand, non-Sephardic Arvits and, on  the other, non-Sabbath Arvits.  The order of  the qualifiers analyzes the Sephardic Sabbath Arvit as  part  of  the Sephardic Arvit liturgy in general.
Using  the  same rules, we  get  "Arvit (Reconstructionist : Sabbath)" for the "Kol ha-neshamah" work being cataloged.
Since there's no conflict (so  far)  for  the  basic heading  "Arvit  (Reconstructionist),"  it's   not  necessary  to  further
qualify this heading (per  rule 25.22A, end  of  the rule)  by  a  second term such as "Federation of Reconstructionist
Congregations and Havurot."