A method of inspecting a blow molded container having a finish, a base, a body between the finish and base, and etching at the base. The method includes identifying where on the base the etching is located, designating the base as accurately blow molded if the etching is located at a predetermined location of the base, and designating the base as not accurately blow molded if the etching is not located at the predetermined location of the base.

A method of inspecting a blow molded container having a finish, a base, a body between the finish and base, and etching at the base. The method includes identifying where on the base the etching is located, designating the base as accurately blow molded if the etching is located at a predetermined location of the base, and designating the base as not accurately blow molded if the etching is not located at the predetermined location of the base.

Container of a bag-in-container type, wherein a neck region of the container is provided with at least one opening extending substantially radially there through, into a space between the outer container and an inner container adjacent thereto, wherein: the neck region is provided with coupling elements, preferably at opposite sides of the at least one opening, seen in circumferential direction, for coupling of a connecting device to the container for introducing a pressure fluid through the at least one opening into a space between the inner and outer container; and/or the at least one opening is provided with or forming part of a first coupler for coupling a pressure fluid feed line to the opening, for pressurizing a space between the inner and outer container.