the input file

 q 'abc\x0103z\\\n';
 d "abc\x0103z\n\n";
 d "abc\x0103z\\\n";
 d "abc\x0103z\n\n";
 d "abc\x0103z\\\n";
 s fred;
 s bill;
 s fred;
 d "abc\x"0103ffee"z\\\n";
 d "abc\x0103z\\\n";
 s _fredBill101a;
 d "abc\x"0103ffee"z\\\n";
 n 100.1e3L;
 n 100.1e3Z;
 n .1e3L;
 s _fredBill101a;

 @ fred;
 @ 1234;
 @ 1234.5;
 @ 'abcd\\x\n\'';
 @ "abcd\\x\n\'";
 @ "abcd\x"0123456789abcdef"z";

 O 77;
 B 101011;
 X 0xa001;
 D 100239;

 e fred;
 e william;
 e alfred;
 e william;
 e alfred;
 e fred;
 f WILliaM;
 f FreD;
 f FRED;
 g FRED;
 g freD;
 g fred;

 E this;
 E what;
 F This;
 F tHIs;
 G this;
 G tHiS;
 G wHAT;

 V Test;
 V test;
 V ZZZZ;
 V Test;

 L "ABCDEefgHxyzD?/!";
 U "ABCDEefgHxyzD?/!";

 x "l:%5B0-9a-zA-Z%20%5d xyz";
 y "l:%5B0-9a-zA-Z%20%5d xyz";

the results

 abc\x0103z\\\n
 0:abc\x0103z\n\n
 1:abc\x0103z\\\n
 0:abc\x0103z\n\n
 1:abc\x0103z\\\n
 2:fred
 3:bill
 2:fred
 4:abc\x"0103ffee"z\\\n
 1:abc\x0103z\\\n
 5:_fredBill101a
 4:abc\x"0103ffee"z\\\n
 100.1e3l
 not recognised: [n100.1e3Z;]
 .1e3l
 5:_fredBill101a
 @buffer:[fred]
 @buffer:[1234]
 @buffer:[1234.5]
 @buffer:[abcd\\x\n\']
 @buffer:[abcd\\x\n\']
 @buffer:[abcd\x"0123456789abcdef"z]
 = octal    :[63]
 = binary   :[43]
 = hex      :[40961]
 = num      :[100239]
 = usym     :[fred->fred:2]
 = usym     :[william->william:6]
 = usym     :[alfred->alfred:7]
 = usym     :[william->william:6]
 = usym     :[alfred->alfred:7]
 = usym     :[fred->fred:2]
 = ulsym    :[WILliaM->william:6]
 = ulsym    :[FreD->fred:2]
 = ulsym    :[FRED->fred:2]
 = uusym    :[FRED->FRED:8]
 = uusym    :[freD->FRED:8]
 = uusym    :[fred->FRED:8]
 = ssym     :[this->this:yes]
 = ssym     :[what->what:no]
 = slsym    :[This->this:yes]
 = slsym    :[tHIs->this:yes]
 = susym    :[this->THIS:yes]
 = susym    :[tHiS->THIS:yes]
 = susym    :[wHAT->WHAT:no]
 = variable :[Test->this:yes]
 = variable :[test->test:no]
 = variable :[ZZZZ->ZZZZ:no]
 = variable :[Test->this:yes]
 = lcase    :[abcdeefghxyzd?/!]
 = ucase    :[ABCDEEFGHXYZD?/!]
 = urn      :[l%3A%255B0-9a-zA-Z%2520%255d%20xyz]
 = urd      :[l:[0-9a-zA-Z ] xyz]