If `use-oldjis' is specified, JIS0208-1976 is designated instead of
JIS0208-1983.")
-;; Fixme: Are translation tables still relevant? (Not currently
-;; implemented, anyway.)
-;; Fixme: What does cons :bom mean? Explanation of :endian.
(defun define-coding-system (name docstring &rest props)
"Define NAME (a symbol) as a coding system with DOCSTRING and attributes.
The remaining arguments must come in pairs ATTRIBUTE VALUE. ATTRIBUTE
mark'. VALUE must nil, t, or cons of coding systems whose
`:coding-type' is `utf-16'.
+If the value is nil, on decoding, don't treat the first two-byte as
+BOM, and on encoding, don't produce BOM bytes.
+
+If the value is t, on decoding, skip the first two-byte as BOM, and on
+encoding, produce BOM bytes accoding to the value of `:endian'.
+
+If the value is cons, on decoding, check the first two-byte. If theyq
+are 0xFE 0xFF, use the car part coding system of the value. If they
+are 0xFF 0xFE, use the car part coding system of the value.
+Otherwise, treat them as bytes for a normal character. On encoding,
+produce BOM bytes accoding to the value of `:endian'.
+
This attribute has a meaning only when `:coding-type' is `utf-16'.
`:endian'
-VALUE must be t or nil. See the above description for the detail.
+VALUE must be `big' or `little' specifying big-endian and
+little-endian respectively. The default value is `big'.
This attribute has a meaning only when `:coding-type' is `utf-16'.