This spell was used by Cuthbert Sinclair in Blade Runners to render a place (his secret hideout) invisible and unplottable. It may be a branch or may be the strongest known form of warding spell. According to Men of Letters's "Infamati et obliterati" (Dishonored and Forgotten) members files, in 1954 (2 years before his "formal separation" in 1956), he found (or maybe invented) this spell and proposed the usage of this spell to render the Men of Letters bunker unplottable and only accessible by a special countering spell. His proposal to use the spell was rejected by Men of Letters and he was kicked out of the organization in 1956. However, that wasn't the end of the spell. He used this spell to render his own mansion invisible and unplottable.