A quick-reference compilation of the information provided at this link, for the purposes of guiding reuse.
Textual summary:
1, 3 and 6 should not be reused (although 1 may be ok in a well-ventilated, non-food context.)
2, 4 and 5 are generally OK to reuse
5 covers most microwavables, and we don't know whether heat transferred from hot food causes any particles or vapors to come out of it yet.
7 is miscellaneous, but includes polycarbonate, which features BPA.
9 is not covered (ABS, which tends to be in forms that aren't very reusable anyway, like shells of LCD monitors, phones, etc). FWIW ABS appears to be safe in non-extreme, non-food uses.
It should also be noted that examples are not uniformly applicable -- eg. some CD/DVD cases are not marked with a recycle code at all.
[Media: 96x96mm card. Markers: Permanent markers, calligraphy marker, 0.4mm pens, try square. average X-height is 5 mm, x-height is 3 mm (making this equivalent precision-wise to a pixel font with X-height of 12.5 pixels)]