The start of 5.5 lists various conversions that are allowed in a casting context.

"Casting contexts allow the use of one of:
• an identity conversion (§5.1.1)
• a widening primitive conversion (§5.1.2)
• a narrowing primitive conversion (§5.1.3)
• a widening and narrowing primitive conversion (§5.1.4)
• a widening reference conversion (§5.1.5) optionally followed by either an unboxing conversion (§5.1.8) or an unchecked conversion (§5.1.9)
• a narrowing reference conversion (§5.1.6) optionally followed by either an unboxing conversion (§5.1.8) or an unchecked conversion (§5.1.9)
• a boxing conversion (§5.1.7) optionally followed by a widening reference conversion (§5.1.5)
• an unboxing conversion (§5.1.8) optionally followed by a widening primitive conversion (§5.1.2)."

 This list has various problems:
- It doesn't include all allowed reference type casts (per 5.5.1), such as from Runnable to Cloneable
- It doesn't allow widening before unboxing followed by primitive widening, even though javac does (see JDK-8166326)
- The use of "widening and narrowing primitive conversion" adds unnecessary complexity, since we could just as easily describe this as "a widening primitive conversion followed by a narrowing primitive conversion". (Cleaning this up means deleting 5.1.4, though, a disruption that may not be worth it.)
- It gives the impression that any listed conversion is allowed, even though some unchecked conversions are not (per 5.5.1)
- It is redundant, since the next paragraph restates it more precisely.

Propose rewriting to merge with the subsequent description and to accurately reflect the set of legal conversions.