:utf-32 implements UTF-32 with control over the byte order. This format maps to one of
:utf-32-reversed as appropriate. If little-endian is supplied, it determines the byte order. Otherwise, if it is used for opening a file, the system checks whether the file starts with the BOM (Byte Order Mark), and uses it if found. Otherwise the big-endian order is used. The system uses the required byte order and the native byte order of the computer it executes on to decide whether to use
:utf-32 formats encounter a surrogate code point or a character code which is too large, they by default signal an error of type external-format-error. If use-replacement is non-nil, they replace the illegal input by the replacement character. When use-replacement is non-nil these formats never signal an error.
These formats were new in LispWorks 7.0. In LispWorks 6.1 and earlier versions there is an undocumented external format
character that works similarly to
:utf-32-native in LispWorks 7.0 and later. This is now mapped to
:utf-32-native to avoid errors in existing code, and should not be used in new code.
LispWorks User Guide and Reference Manual - 20 Sep 2017