This is an announcement for the paper "On separable determination of sigma-P-porous sets in Banach spaces" by Marek Cuth, Martin Rmoutil, and Miroslav Zeleny. Abstract: We use a method involving elementary submodels and a partial converse of Foran lemma to prove separable reduction theorems concerning Suslin sigma-P-porous sets where "P" can be from a rather wide class of porosity-like relations in complete metric spaces. In particular, we separably reduce the notion of Suslin cone small set in Asplund spaces. As an application we prove a theorem stating that a continuous approximately convex function on an Asplund space is Frechet differentiable up to a cone small set. Archive classification: math.FA Mathematics Subject Classification: 46B26, 28A05, 54E35, 58C20 Submitted from: cuthm5am@karlin.mff.cuni.cz The paper may be downloaded from the archive by web browser from URL http://front.math.ucdavis.edu/1309.2174 or http://arXiv.org/abs/1309.2174