are configured to mate and self align with a corresponding number of second engagement features 132 of a structure in some examples the structure can include another carrier for instance another first carrier 100 configured to carry store or otherwise receive at least one first scaffolding component in other examples the structure includes a carrier configured to carry store or otherwise receive at least one scaffolding component different from the first scaffolding component in an example the one or more second engagement features 132 include cup like receptacles in a further example one or more second engagement features 132 are disposed at a top of the first carrier 100 in a still further example the first carrier 100 includes a second engagement feature 132 at each of the top corners of the first carrier 100 to correspond with the first engagement features 130 of another first carrier 100 in an example each of the second engagement features 132 includes walls 132 a see fig7 extending from a base 132 b to an opening 132 c in a further example the walls 132 a taper slightly outwardly such that the opening 132 c of the second engagement feature 132 is larger in area than the base 132 b of the second engagement feature 132 in some examples two first carriers 100 are stackable with the first engagement features 130 of one.