  Enhanced production of hadrons with $s$-quark content has been observed in
$pp$ collisions at LHC, and earlier in collisions of heavy nuclei. We review
the string hadronisation formalism and correc- tions from rope hadronisation
and colour reconnection, corrections that takes place in such dense
environments, and are able to correctly describe data. Since such corrections
are very sensitive to the modelling of transverse proton structure, we
investigate two such models, and compare to final states. Finally we describe
how such corrections can also give a possible explanation to collective
phenomena observed in small systems.
