apps/openssl.cnf and the documentation say it's "nombstr",

but crypto/asn1/a_strnid.c had "nombchar".

apps/req.c

@@ -500,7 +500,7 @@ bad:
 	p = CONF_get_string(req_conf, SECTION, STRING_MASK);
 
 	if(p && !ASN1_STRING_set_default_mask_asc(p)) {
-		BIO_printf(bio_err, "Invalid global string mask setting %s", p);
+		BIO_printf(bio_err, "Invalid global string mask setting %s\n", p);
 		goto end;
 	}
 

crypto/asn1/a_strnid.c

@@ -103,7 +103,7 @@ int ASN1_STRING_set_default_mask_asc(char *p)
 		if(!p[5]) return 0;
 		mask = strtoul(p + 5, &end, 0);
 		if(*end) return 0;
-	} else if(!strcmp(p, "nombchar"))
+	} else if(!strcmp(p, "nombstr"))
 			 mask = ~(B_ASN1_BMPSTRING|B_ASN1_UTF8STRING);
 	else if(!strcmp(p, "pkix"))
 			mask = ~B_ASN1_T61STRING;