Verified: If you properly define custom fonts, EPUB implementation on PRS-505 does render proper italics.
Code:
@font-face { font-family: "Times CE", serif; font-weight: normal; font-style: normal; font-variant: normal, small-caps; src: url(res:///Data/fonts/times.ttf); }
@font-face { font-family: "Times CE", serif; font-weight: bold; font-style: normal; font-variant: normal, small-caps; src: url(res:///Data/fonts/timesbd.ttf); }
@font-face { font-family: "Times CE", serif; font-weight: normal; font-style: italic; font-variant: normal, small-caps; src: url(res:///Data/fonts/timesi.ttf); }
@font-face { font-family: "Times CE", serif; font-weight: bold; font-style: italic; font-variant: normal, small-caps; src: url(res:///Data/fonts/timesbi.ttf); }