diff --git a/qse/include/qse/cmn/opt.h b/qse/include/qse/cmn/opt.h
index 98013236..e49976ac 100644
--- a/qse/include/qse/cmn/opt.h
+++ b/qse/include/qse/cmn/opt.h
@@ -66,8 +66,13 @@ struct qse_opt_t
 
 
 /* --------------------------------------------------------------------- */
-#define QSE_CLI_OPTNAME (1 << 0)
-#define QSE_CLI_OPTVAL  (1 << 1)
+enum qse_cli_optflag_t
+{
+	QSE_CLI_REQUIRE_OPTNAME      = (1 << 0), /* if set, the option itself is require */
+	QSE_CLI_REQUIRE_OPTVAL       = (1 << 1), /* if set, the option's value is mandatory */
+	QSE_CLI_DISCRETIONARY_OPTVAL = (1 << 2)  /* if set, the option's value is optional. */
+};
+typedef enum qse_cli_optflag_t qse_cli_optflag_t;
 
 enum qse_cli_error_code_t
 {
@@ -86,7 +91,7 @@ struct qse_cli_opt_t
 {
 	/* input */
 	const qse_char_t* name;
-	int requires;
+	int optflags; /* 0 or bitwise-ORed of qse_cli_optflags_t enumerartors */
 
 	/* output - you don't have to initialize this field */
 	qse_char_t* value;
diff --git a/qse/include/qse/si/log.h b/qse/include/qse/si/log.h
index c776b20c..3126ec5d 100644
--- a/qse/include/qse/si/log.h
+++ b/qse/include/qse/si/log.h
@@ -57,7 +57,7 @@
 
 /* options */
 #define QSE_LOG_KEEP_FILE_OPEN        (1 << 13)
-#define QSE_LOG_MASKED_PRIORITY         (1 << 14)
+#define QSE_LOG_MASKED_PRIORITY       (1 << 14)
 #define QSE_LOG_INCLUDE_PID           (1 << 15)
 #define QSE_LOG_HOST_IN_REMOTE_SYSLOG (1 << 16)
 
diff --git a/qse/lib/cmn/opt-cli.c b/qse/lib/cmn/opt-cli.c
index 18d42c15..1c110649 100644
--- a/qse/lib/cmn/opt-cli.c
+++ b/qse/lib/cmn/opt-cli.c
@@ -124,7 +124,7 @@ int qse_parsecli (qse_cli_t* cli, qse_mmgr_t* mmgr, int argc, qse_char_t* const
 			}
 			else 
 			{
-				if (value && !(opt->requires & QSE_CLI_OPTVAL)) 
+				if (value && !(opt->optflags & (QSE_CLI_REQUIRE_OPTVAL | QSE_CLI_DISCRETIONARY_OPTVAL))) 
 				{
 					if (cli->data.errcb(cli, QSE_CLI_ERROR_REDUNDANT_OPTVAL, name.ptr, value) <= -1) 
 					{
@@ -132,7 +132,7 @@ int qse_parsecli (qse_cli_t* cli, qse_mmgr_t* mmgr, int argc, qse_char_t* const
 						return -1;
 					}
 				}
-				else if (!value && (opt->requires & QSE_CLI_OPTVAL)) 
+				else if (!value && (opt->optflags & QSE_CLI_REQUIRE_OPTVAL)) 
 				{
 					if (cli->data.errcb(cli, QSE_CLI_ERROR_MISSING_OPTVAL, name.ptr, value) <= -1) 
 					{
@@ -175,7 +175,7 @@ int qse_parsecli (qse_cli_t* cli, qse_mmgr_t* mmgr, int argc, qse_char_t* const
 
 	for (opt = cli->data.opts; opt->name != QSE_NULL; opt++) 
 	{
-		if ((opt->requires & QSE_CLI_OPTNAME) && opt->value == QSE_NULL) 
+		if ((opt->optflags & QSE_CLI_REQUIRE_OPTNAME) && opt->value == QSE_NULL) 
 		{
 			if (cli->data.errcb(cli, QSE_CLI_ERROR_MISSING_OPTNAME, opt->name, QSE_NULL) <= -1) 
 			{
diff --git a/qse/lib/si/App.cpp b/qse/lib/si/App.cpp
index 112e69d9..2217008b 100644
--- a/qse/lib/si/App.cpp
+++ b/qse/lib/si/App.cpp
@@ -136,12 +136,12 @@ int App::daemonize (bool chdir_to_root, int fork_count, bool root_only) QSE_CPP_
 	{
 		int keep[] = { 0, 1, 2};
 
-		if (qse_close_open_fds_using_proc (keep, QSE_COUNTOF(keep)) <= -1)
+		if (qse_close_open_fds_using_proc(keep, QSE_COUNTOF(keep)) <= -1)
 		{
 			for (int i = qse_get_highest_fd(); i >= 3; i--) QSE_CLOSE (i);
 		}
 
-		int fd = QSE_OPEN ("/dev/null", O_RDWR, 0);
+		int fd = QSE_OPEN("/dev/null", O_RDWR, 0);
 		if (fd >= 0)
 		{
 			if (fd != 0) QSE_DUP2 (fd, 0);