These are found hanging from the bridges and railings throughout the city of Vivec. They bear transcriptions written in the Daedric Alphabet. Most of the inscriptions are taken from The Book of Dawn and Dusk.
This banner just says
"Arena", followed by a 'V' (for 'Vivec'?) and can predictably be found around the
Arena Canton.
"Speak none but good of gods"
"Walk in the presence of your lords"
"AVS in evey hour"
(The 'r' in 'every' appears to be missing for some reason.)
"No child has sinner heart"
"Comfort is given, justice is taken"
"Count only happy hours"
(The second 'p' in 'happy' and the 'h' in 'hours' are mirrored from their usual orientation.)