SWIMS
Ambigrams
madamracecarmalayalam
SWIMS (:
I'm not sure exactly what you mean. I guess you could write the letters upside down. If you write the words upside down, the letters will be in reverse order and won't cross correctly. Most crosswords have 180 degree symmetry, so if you turn the puzzle upside down, you could enter the words but the numbers won't line up. The bottom line is you can do whatever you want, but you will have diminishing success in actually finishing the puzzle, which is mostly the point for me.
This is how you would spell it: upside down. I hope this helps!!
Australia's shape looks a little like an upside down sheep.
SWIMS
Because if you turn a nine upside down then it does not look like anything but if you turn a six upside down then it looks like a nine.
A Trackball.
SIS
86 which upside down looks like 98. Difference between them is 12
upside horseshoe on the car
trac ball.
An ambigram.
Florida looks like an upside-down "L"
Well when a word is shown in front of a mirror the reflection of the word upside down. This is called mirror image.