In version 6.5 of 4th Dimension, the maximum length of variable names is now 30 characters, including the prefix characters $ or <>. In 4D V6, the limit was 31 characters, and this did not include the $ or <> symbols.
The new limit also applies to the names of semaphores. (In 4D V6, a semaphore name was limited to 15 characters.)
A list item can now contain up to 255 characters. (In 4D V6, the limit was 30 characters.)
These changes are documented in the 4th Dimension 6.5 Upgrade manual.