A pack

A stack indexable lidded container formed from (i) a main blank sheet of material which defines at least the following (a) a generally square or rectangular base (save possibly for corner truncations thereof), (b) at least a pair of opposite walls (hereafter "side walls") and (c) a lidding flap from each such side wall, (ii) a blank of sheet material to provide a first wall (hereafter "end wall") other than a said side wall, and (iii) a blank of sheet material to provide a second wall (i.e. "second end wall") other than a said side wall; wherein said main blank and each end wall blank in the erected container together, as a result of their being coupled together at and/or adjacent the corner of said generally square or rectangular base (save possibly for corner truncations) thereof, define a corner column ("column" being as hereinbefore defined) structure at and/or adjacent each such corner; and wherein said end walls each defines an indexing upstand (hereafter "indexing projection") centrally thereof such that the pair of such upstands (one on each end wall) is receivable by a like container stacked thereon for indexing purposes, and wherein each end wall includes an inturned upper flange each having an opening therein on either side of the proximate indexing projection, each opening being adapted to receive a locking tab of the proximate lidding flap, the construction and arrangement being such that in an erected container, when the lidding flaps are closed, each end of each lidding flap is locked by a tab that has passed down into such an opening of an inturned flange, and such that each such tab can be uplifted from such an engagement to allow the opening of the container.