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A conventional superconductor is described by a single complex order parameter field which has two fundamental length scales, the magnetic field penetration depth λ and the coherence length ξ. Their ratio κ determines the response of a superconductor to an external field, sorting them into two categories as follows; type-I when κ<1/2 and type-II when κ>1/2. We overview here multicomponent systems which can possess three or more fundamental length scales and allow a separate “type-1.5” superconducting state when, e.g. in two-component case ξ₁<2λ<ξ₂. In that state, as a consequence of the extra fundamental length scale, vortices attract one another at long range but repel at shorter ranges. As a consequence the system should form an additional Semi-Meissner state which properties we discuss below. In that state vortices form clusters in low magnetic fields. Inside the cluster one of the component is …