QUARK:
Advanced Options.
Exclude fragments: QUARK models are built from small fragments (1-20 residues long) taken from known PDB structures (template). If "remove fragments from protein sharing >30% sequence identity with target" was choosen, fragments will not be generated from template structures that are highly homologous to target sequence. In general, excluding homologous templates will make structure prediction harder. So this option is only for benchmarking purposes.