Gradual itemsets of the form " the more/less A, the more/less B " summarise data through the description of their internal tendencies, identified as correlation between attribute values. This paper proposes to characterise gradual itemsets, enriching them with an additional clause introduced by the linguistic expression " especially if " : they are of the form " the more/less A, the more/less B, especially if J ∈ R " , where J is a set of attributes occurring in A ∪ B and R is a set of intervals defined for each attribute in J. The method proposed to automatically extract characterised gradual itemsets is based on appropriate mathematical morphology tools. The paper illustrates the relevance of the proposed approach on a real data set.