In time computers added support for more than one alphabet by introducing character sets with both upper and lower case letters, along with convenient ways to both input and display these.
In UPPER stropping the bold letters in bold word are represented by upper-case letters, whereas the letters in tags are represented by lower-case letters.
The notions of upper- and lower-case are not applicable to digits, but since the language syntax assures that it is not possible to have a bold word that starts with a digit, digits are considered to be bold if they follow a bold letter or another bold digit.
Below is the recsel output records procedure again, this time
encoded in UPPER stropping.
PROC recsel output records = VOID:
BEGIN BITS flags
:= (include descriptors | rec f descriptor | rec f none);
RECRSET res = rec db query (db, recutl type,
recutl quick, flags);
RECWRITER writer := rec writer file new (stdout);
skip comments of writer := TRUE;
IF recutl print sexps
THEN mode OF writer := rec writer sexp FI;
rec write (writer, res)
END
Note how in this regime it is almost never necessary to introduce bold tags with points. All in all, it looks much more natural to contemporary readers. UPPER stropping is in fact the stropping regime of choice today. It is difficult to think of any reason why anyone would resort to use POINT or RES stropping.