The faction is believed to have formed after the release of the Finsbury Option Amendments of 1988, with the explicit manifesto of rejecting these amendments. Their name stems from the creation, postulated as part of the Amendments, of a quadrant five, which the Quadranters adopted as the symbol of all that they disliked about the ruleset. Not for the first time in history, we see a pressure group that could only define itself by what it was against – in this case the logical semantic inconsistency of having five divisions called 'quadrants', in spite of the significant utility of the proposed division.
When the Holland Park 2000 ruleset was released, the Fifth Quadranters grudgingly disbanded, on the grounds that the offensive features of the Amendments had been finally been altered to an acceptable state or removed. In fact, Holland Park 2000 does still use a 'central' quadrant five, but it appears the Quadranters have been able to reconcile themselves to it by referring to it as the hub. In fact, Holland Park 2000 retains about a third of the Finsbury Amendments, including the actual Finsbury Option itself, which gave the Amendments their name but only ever formed a minor part of them.
Rumours that some of the former Quadranters had banded together with remnants of the discredited CAMREC 'old guard' of the 1960s, and infiltrated the IMCS have been explicitly denied. Their intention was supposedly to sabotage the discussions of revisions and updates to Holland Park 2000 and thus erode the credibility of the IMCS by introducing errors into the final typesetting and turning an 'official blind eye' to logical inconsistencies. On the whole, the IMCS has generally been viewed as the victor in most of its recent clashes with CAMREC. This remains the case in spite of the brief re-emergence of the notorious Mornington Crescent Loop in the second round of the Holland Park 2000 amendments. The problem was hastily corrected in the third set of amendments, issued barely a week later.