Bingley's use of viz. here, although it is only a reference to his use, is the 37th(!) use in these forums over the last five(5) years. jheem used it most often (during his salad days) followed by yours truly, milum and Bingley. Defoe doesn't even rate a citation in OED2.

viz. [Abbrev. of VIDELICET. Cf. VIDZ
The z represents the ordinary med.L. symbol of contraction for et or -et. For the various forms in which the abbreviation occurs in med.L. manuscripts, see Chassant Dict. des Abréviations and Cappelli Dizionario di Abbreviature. In reading aloud usually rendered by ‘namely’.]