Update PLATFORMS.md

Co-authored-by: Spencer Wilson <[email protected]>

PLATFORMS.md

@@ -8,7 +8,7 @@ This classification is roughly based on the [rust platform support tier classifi
 
 ### Tier 1
 
-Tier 1 targets can be thought of as "guaranteed to work". The CI system builds and tests binary versions for each tier 1 target to make sure any change does not negatively affect those platforms. Platform-specific build documentation must exist. Tier 1 targets marked with an asterisk are additionally tested for constant-time behaviour. The CI system contains automated constant-time testing for each of these starred targets, and all failures are documented in the `tests/constant_time` directory. IMPORTANT: This does not mean that constant-time behaviour is guaranteed on these targets, or that non-constant-time behaviour is limited to documented exceptions. It does, however, mean that `liboqs` developers should track constant-time issues on these platforms.
+Tier 1 targets can be thought of as "guaranteed to work". The CI system builds and tests binary versions for each tier 1 target to make sure any change does not negatively affect those platforms. Platform-specific build documentation must exist. Tier 1 targets marked with a dagger (†) are additionally tested for constant-time behaviour. The CI system contains automated constant-time testing for each of these starred targets, and all failures are documented in the `tests/constant_time` directory. IMPORTANT: This does not mean that constant-time behaviour is guaranteed on these targets, or that non-constant-time behaviour is limited to documented exceptions. It does, however, mean that `liboqs` developers should track constant-time issues on these platforms.
 
 ### Tier 2