The concept of 'class lines' was discussed briefly in another thread, but it may be worth revisiting.
What positions do other communists view as immutable or prerequisites for membership in a communist organization?
There's always differences over certain positions or tactics going back to the Communist League- and a long history within the worker's movement of tendencies, factions and minorities within parties or organizations. But apart from issues most communists would argue are 'class lines' (positions which place someone either in the company of leftists or on the side of communists) there's a lot of other 'big' positions or concepts which divide communists:
-Differences over the conception of decadence (high OCC, saturation of pre-capitalist markets, transition from formal to real domination of capital).
-Difference over when or how the party is created (during or before a pre-revolutionary situation).
I'd be very interested to hear others' thoughts on which issues, positions or theories require homogenous acceptance by all communists if they inhabit the same organization, and which positions-concepts-theories are tangential or secondary in the sense that there can be disagreement on them in an organization.