Multi-brand assortment
A multi-brand assortment is an assortment of toys typically released in multiple waves, with the individual toys from different waves being branded as part of different toy lines or franchises. In other cases, toys within the same wave are branded as part of different toy lines or franchises.
Typically, whenever Hasbro launches a new toy line, all the various size classes are reset and relaunched with new assortment numbers for the new line, regardless of whether they are sold at the same price point or not. This makes sense from a marketing standpoint, as it signalizes to retailers "Hey, this is new product, completely different from the old product".
However, in some instances, an assortment is continued under a new line's banner with new product. This mostly applies to store exclusive assortments and side lines that only have one wave per franchise; because the figures in a subsequent wave are sold at the same price point, Hasbro decides to simply continue the assortment rather than reset it.
This is similar, but not identical to rebranding: Instead of rebranding the figures (or rather their packaging) themselves, the assortment is rebranded, but the actual products sold under different brands are not the same. It's also not the same thing as a subline imprint, which is still marketed as part of the same main line or franchise.
Examples

- The 2000 Beast Machines Deluxe (assortment number 80465) and Ultra (assortment number 80475) assortments mixed Dinobots-branded figures with Beast Machines-branded ones within the same waves. Both shared the same general packaging design template, but the Dinobots figures lacked the Beast Machines branding.
- The KB Toys exclusive Deluxe assortment that contained Energon-branded redecos of Armada Demolishor and Cyclonus was given a second wave the following year branded as part of the Universe line (though with the packaging sporting various design elements taken from the concurrently released Cybertron line) that contained redecos of Energon Downshift and Snow Cat, sold under the same assortment number (27271).
- In Europe, the Micromaster Sixteams were not sold in Universe packaging like their KB Toys exclusive US market counterparts, but in Energon (Protectobots, Constructicons) and Cybertron (Railbots, Aerialbots) packaging. Although the European packaging sported no assortment numbers, the instructions featured the same assortment number (29460) as the American versions for all four waves.
- The Titanium Series 3" Robot Masters figures arguably count; for the first seven waves, the assortment was released as part of its own line, sporting the Transformers title in the font used by a plethora of lines from 2001 through early 2007; but for the final three waves, it added characters from the live-action film series, with the packaging being accordingly redesigned to match the standardized look of the 2007 Transformers movie toy line (an instance of co-branding), while retaining the same assortment number (33901).
- The 6" PVC Titan Guardians assortment released under the Beast Hunters brand, consisting of Optimus Prime, Bumblebee, Megatron and Shockwave, was given a second wave (now named "Titan Warriors") under the 2014 Transformers line, this time with Generation 1 versions of Optimus Prime, Megatron, Starscream and Soundwave, all of them sporting the same assortment number (A6107).

