Putto best-known are the sculptor Donatello and the painter Raphael. The two relaxed and curious putti who appear at the foot of Raphael's Sistine Madonna are often reproduced. They also experienced a major revival in the 19th century, where they gamboled through paintings by French academic painters, from Gustave Doré’s illustrations for "Orlando Furioso" to advertisements. The iconography of putti is deliberately unfixed, so that it is difficult to tell the difference between putti, cupids, and various forms of angels. They have no unique, immediately identifiable attributes, so that putti may have many meanings and roles in the context of art.
Plural form of words ending in -us "omnis", and "ignoramus" is a verb form, 'we do not know'. "Syllabus" is a Late Latin (16th c.) word, derived from a misreading of the Greek "sittybos" "table of contents"; since it is not a classical word, it does not have a classical plural. The English plural of "virus" is "viruses". In most speaking communities, this is non-controversial and speakers would not attempt to use the non-standard plural in -"i". However, in computer enthusiast circles in the late 20th century and early 21st, the non-standard "viri" form (sometimes even "virii") was well-attested, generally in the context of computer viruses. "Viri"