diff --git a/gendelims.go b/gendelims.go
new file mode 100644
index 0000000..9e0f1fc
--- /dev/null
+++ b/gendelims.go
@@ -0,0 +1,13 @@
+package rfc3986
+
+// IsGenDelim returns true if the value of 'r' matches 'sub-delims' as defined in IETF RFC-3986:
+//
+//	gen-delims  = ":" / "/" / "?" / "#" / "[" / "]" / "@"
+func IsGenDelim(r rune) bool {
+	switch r {
+	case          ':' , '/' , '?' , '#' , '[' , ']' , '@':
+		return true
+	default:
+		return false
+	}
+}
diff --git a/gendelims_test.go b/gendelims_test.go
new file mode 100644
index 0000000..005e92e
--- /dev/null
+++ b/gendelims_test.go
@@ -0,0 +1,51 @@
+package rfc3986_test
+
+import (
+	"testing"
+
+	"sourcecode.social/reiver/go-rfc3986"
+)
+
+func TestIsGenDelim(t *testing.T) {
+
+	tests := []struct{
+		Rune rune
+		Expected bool
+	}{
+	}
+
+	for r:=rune(0); r < rune(8192); r++ {
+		test := struct{
+			Rune rune
+			Expected bool
+		}{
+			Rune: r,
+			Expected: false,
+		}
+
+		if ':' == r ||
+		   '/' == r ||
+		   '?' == r ||
+		   '#' == r ||
+		   '[' == r ||
+		   ']' == r ||
+		   '@' == r {
+			test.Expected = true
+		}
+
+		tests = append(tests, test)
+	}
+
+	for testNumber, test := range tests {
+		actual := rfc3986.IsGenDelim(test.Rune)
+		expected := test.Expected
+
+		if expected != actual {
+			t.Errorf("For test #%d, the actual value for rfc3986.IsGenDelim() is not what was expected.", testNumber)
+			t.Logf("EXPECTED: %t", expected)
+			t.Logf("ACTUAL:   %t", actual)
+			t.Logf("RUNE: (%U) %q", test.Rune, string(test.Rune))
+			continue
+		}
+	}
+}
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..5fbc7eb
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module sourcecode.social/reiver/go-rfc3986
+
+go 1.20
diff --git a/reserved.go b/reserved.go
new file mode 100644
index 0000000..4c5839f
--- /dev/null
+++ b/reserved.go
@@ -0,0 +1,12 @@
+package rfc3986
+
+// IsReserved returns true if value of 'r' matches 'reserved' as defined in IETF RFC-3986:
+//
+//	reserved    = gen-delims / sub-delims
+//	
+//	gen-delims  = ":" / "/" / "?" / "#" / "[" / "]" / "@"
+//	
+//	sub-delims  = "!" / "$" / "&" / "'" / "(" / ")" / "*" / "+" / "," / ";" / "="
+func IsReserved(r rune) bool {
+	return IsGenDelim(r) || IsSubDelim(r)
+}
diff --git a/subdelims.go b/subdelims.go
new file mode 100644
index 0000000..0ac18b4
--- /dev/null
+++ b/subdelims.go
@@ -0,0 +1,13 @@
+package rfc3986
+
+// IsSubDelim returns true if the value of 'r' matches 'sub-delims' as defined in IETF RFC-3986:
+//
+//	sub-delims  = "!" / "$" / "&" / "'" / "(" / ")" / "*" / "+" / "," / ";" / "="
+func IsSubDelim(r rune) bool {
+	switch r {
+	case          '!' , '$' , '&' ,'\'' , '(' , ')' , '*' , '+' , ',' , ';' , '=':
+		return true
+	default:
+		return false
+	}
+}
diff --git a/subdelims_test.go b/subdelims_test.go
new file mode 100644
index 0000000..701e221
--- /dev/null
+++ b/subdelims_test.go
@@ -0,0 +1,55 @@
+package rfc3986_test
+
+import (
+	"testing"
+
+	"sourcecode.social/reiver/go-rfc3986"
+)
+
+func TestIsSubDelim(t *testing.T) {
+
+	tests := []struct{
+		Rune rune
+		Expected bool
+	}{
+	}
+
+	for r:=rune(0); r < rune(8192); r++ {
+		test := struct{
+			Rune rune
+			Expected bool
+		}{
+			Rune: r,
+			Expected: false,
+		}
+
+		if '!' == r ||
+		   '$' == r ||
+		   '&' == r ||
+		  '\'' == r ||
+		   '(' == r ||
+		   ')' == r ||
+		   '*' == r ||
+		   '+' == r ||
+		   ',' == r ||
+		   ';' == r ||
+		   '=' == r {
+			test.Expected = true
+		}
+
+		tests = append(tests, test)
+	}
+
+	for testNumber, test := range tests {
+		actual := rfc3986.IsSubDelim(test.Rune)
+		expected := test.Expected
+
+		if expected != actual {
+			t.Errorf("For test #%d, the actual value for rfc3986.IsSubDelim() is not what was expected.", testNumber)
+			t.Logf("EXPECTED: %t", expected)
+			t.Logf("ACTUAL:   %t", actual)
+			t.Logf("RUNE: (%U) %q", test.Rune, string(test.Rune))
+			continue
+		}
+	}
+}