The SCA Kingdom of Lochac is a formally organised and highly self-governing SCA uber-group covering Australia, New Zealand and their Antarctic territories.
Under SCA administration, Kingdoms can have as few as 400 people (Lochac has 1,500+ paid members with many additional non-subscribing participants); many subgroups (Lochac has 12 Baronies, 5 Shires and many Colleges, Cantons and Hamlets); has landed Royalty (the Crown, typically a King and Queen) who ordinarily serve a six-month term and are chosen by winning a rattan-based (“heavy”) tournament. The Kingdom has no parent group, other than the SCA itself and the affiliated legal entities which cover mundane operational matters in our countries (SCA Ltd and SCA NZ Inc), which each in turn have affiliation agreements with the SCA Inc in the US, managed by the SCA BoD - Board of Directors.
A Principality is defined as a formally organised and self-governing group within a parent Kingdom, with as few as 100 people but typically more; consisting of several sub-groups such as Shires or Baronies; and with a local landed Royalty (the Coronet, traditionally Prince & Princess but gender is now unimportant) who typically serve a defined less-than-a-year term and who, under present rules, are chosen by winning a rattan-based tournament held for that purpose
A Principality is organised around a pre-existing sense of identity and affiliation (eg cultural, geographical, national). Within a new Principality, life continues much the same: group Councils govern group activities; the Crown visits when They can; groups can hold Crown events; the Kingdom levy and all Kingdom-administered services still apply; Principality members can still enter Crown Tournaments and hold Kingdom Offices etc.
There is a new layer of Royalty (the Coronet pair) and Principality Officers (six currently required). The Principality Officers work with and support their equivalent sub-group officers, collect reports, and themselves report to the Coronet and to their equivalent Kingdom Officers. There is some room for agreed-upon variation in all this, defined by local Kingdom and Principality laws.
Principalities can have their own non-armigerous awards, dispensed by the Coronet. These are discussed and developed within and by the Principality itself, with support from Kingdom entities as appropriate. The Crown may also delegate presentation of some defined Kingdom-level awards to a Coronet.
A Crown Principality (CP) is a Principality only in name, headed by the King and Queen who act as Prince and Princess; it has no laws and typically few or no Officers nor, usually, a local formal head. It is not recognised or defined within Corpora. It tends to be an optional placeholder while groups work toward full Principality status. (This is the stay in the basement option the TirMarans eventually chose in 2008; ref pg 1 of the full Principality Discussion document.)
Sometimes Crowns will permit CPs to have ceremonial heads; typically Vice-Reigns chosen by rattan combat or some other means. (The Aethelmearc CP had an appointed Lady Protector for a few months until the group went full Principality.) A CP with Vice-Reigns provides some in-game pageantry positives - but there are significant limitations on vice-regal capabilities which reduce their role compared to a Coronet. Also this approach if used long term would not address the strategic or administrative issues that a full Principality could (see below).