demarcation
noun
( US also demarkation) uk/ˌdiːmɑːˈkeɪʃən/ us/-mɑːr-/ [ C or U ]
a line or rule that shows the limits of something or how things are divided, or the act of dividing something in a particular way:
Careful market demarcation is an essential element of all strategic sales planning.
The bank is establishing a clear line of demarcation between its investment and retail banking businesses.
[ U ] HR
a division of jobs, in which each job can only be done by members of a particular trade union or members who have a particular position in a union:
The restructuring of the company has challenged the union's traditional demarcation lines.