diff --git a/version/bytes_tolerant.go b/version/bytes_tolerant.go
new file mode 100644
index 0000000..e2279d4
--- /dev/null
+++ b/version/bytes_tolerant.go
@@ -0,0 +1,30 @@
+package version
+
+import (
+	"sourcecode.social/reiver/go-rfc2616/sp"
+)
+
+func BytesTolerant(p []byte) (result []byte, rest []byte, ok bool) {
+
+	if len(p) <= 0 {
+		return nil, nil, true
+	}
+
+	{
+		p0 := p[0]
+
+		if sp.ByteIsTolerant(p0) || '\r' == p0 || '\n' == p0{
+			return nil, p, true
+		}
+	}
+
+	{
+		for i,b := range p {
+			if sp.ByteIsTolerant(b) || '\r' == b || '\n' == b {
+				return p[:i], p[i:], true
+			}
+		}
+
+		return p, nil, true
+	}
+}
diff --git a/version/bytes_tolerant_test.go b/version/bytes_tolerant_test.go
new file mode 100644
index 0000000..2396c58
--- /dev/null
+++ b/version/bytes_tolerant_test.go
@@ -0,0 +1,373 @@
+package version_test
+
+import (
+	"testing"
+
+	"bytes"
+
+	"sourcecode.social/reiver/go-rfc2616/version"
+)
+
+func TestBytesTolerant(t *testing.T) {
+
+	tests := []struct{
+		Value []byte
+		ExpectedResult []byte
+		ExpectedRest []byte
+		ExpectedOK bool
+	}{
+		{
+			Value: nil,
+			ExpectedResult: nil,
+			ExpectedRest: nil,
+			ExpectedOK: true,
+		},
+		{
+			Value: []byte(nil),
+			ExpectedResult: nil,
+			ExpectedRest: nil,
+			ExpectedOK: true,
+		},
+
+
+
+		{
+			Value: []byte{},
+			ExpectedResult: nil,
+			ExpectedRest: nil,
+			ExpectedOK: true,
+		},
+		{
+			Value: []byte(""),
+			ExpectedResult: nil,
+			ExpectedRest: nil,
+			ExpectedOK: true,
+		},
+
+
+
+		{
+			Value:        []byte(" "),
+			ExpectedResult: nil,
+			ExpectedRest: []byte(" "),
+			ExpectedOK: true,
+		},
+		{
+			Value:        []byte("\t"),
+			ExpectedResult: nil,
+			ExpectedRest: []byte("\t"),
+			ExpectedOK: true,
+		},
+		{
+			Value:        []byte("\r"),
+			ExpectedResult: []byte(""),
+			ExpectedRest: []byte("\r"),
+			ExpectedOK: true,
+		},
+		{
+			Value: []byte("\n"),
+			ExpectedResult: []byte(""),
+			ExpectedRest: []byte("\n"),
+			ExpectedOK: true,
+		},
+
+
+
+		{
+			Value:          []byte("HTTP/1.1"),
+			ExpectedResult: []byte("HTTP/1.1"),
+			ExpectedRest: nil,
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("HTTP/1"),
+			ExpectedResult: []byte("HTTP/1"),
+			ExpectedRest: nil,
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("finger/1"),
+			ExpectedResult: []byte("finger/1"),
+			ExpectedRest: nil,
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("finger"),
+			ExpectedResult: []byte("finger"),
+			ExpectedRest: nil,
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("1.22.333"),
+			ExpectedResult: []byte("1.22.333"),
+			ExpectedRest: nil,
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("v12.23.34"),
+			ExpectedResult: []byte("v12.23.34"),
+			ExpectedRest: nil,
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte(`()<>@,;:\"/[]?={}`),
+			ExpectedResult: []byte(`()<>@,;:\"/[]?={}`),
+			ExpectedRest: nil,
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("😈"),
+			ExpectedResult: []byte(`😈`),
+			ExpectedRest: nil,
+			ExpectedOK: true,
+		},
+
+
+
+		{
+			Value:          []byte("HTTP/1.1 "),
+			ExpectedResult: []byte("HTTP/1.1"),
+			ExpectedRest:          []byte(" "),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("HTTP/1 "),
+			ExpectedResult: []byte("HTTP/1"),
+			ExpectedRest:         []byte(" "),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("finger/1 "),
+			ExpectedResult: []byte("finger/1"),
+			ExpectedRest:      []byte(" "),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("finger "),
+			ExpectedResult: []byte("finger"),
+			ExpectedRest:       []byte(" "),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("1.22.333 "),
+			ExpectedResult: []byte("1.22.333"),
+			ExpectedRest:        []byte(" "),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("v12.23.34 "),
+			ExpectedResult: []byte("v12.23.34"),
+			ExpectedRest:       []byte(" "),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte(`()<>@,;:\"/[]?={} `),
+			ExpectedResult: []byte(`()<>@,;:\"/[]?={}`),
+			ExpectedRest:                    []byte(` `),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("😈 "),
+			ExpectedResult: []byte(`😈`),
+			ExpectedRest:     []byte(" "),
+			ExpectedOK: true,
+		},
+
+
+
+		{
+			Value:          []byte("HTTP/1.1\t"),
+			ExpectedResult: []byte("HTTP/1.1"),
+			ExpectedRest:          []byte("\t"),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("HTTP/1\t"),
+			ExpectedResult: []byte("HTTP/1"),
+			ExpectedRest:         []byte("\t"),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("finger/1\t"),
+			ExpectedResult: []byte("finger/1"),
+			ExpectedRest:      []byte("\t"),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("finger\t"),
+			ExpectedResult: []byte("finger"),
+			ExpectedRest:       []byte("\t"),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("1.22.333\t"),
+			ExpectedResult: []byte("1.22.333"),
+			ExpectedRest:        []byte("\t"),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("v12.23.34\t"),
+			ExpectedResult: []byte("v12.23.34"),
+			ExpectedRest:       []byte("\t"),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte(`()<>@,;:\"/[]?={} `),
+			ExpectedResult: []byte(`()<>@,;:\"/[]?={}`),
+			ExpectedRest:                    []byte(` `),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("😈\t"),
+			ExpectedResult: []byte(`😈`),
+			ExpectedRest:     []byte("\t"),
+			ExpectedOK: true,
+		},
+
+
+
+		{
+			Value:          []byte("HTTP/1.1\r"),
+			ExpectedResult: []byte("HTTP/1.1"),
+			ExpectedRest:          []byte("\r"),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("HTTP/1\r"),
+			ExpectedResult: []byte("HTTP/1"),
+			ExpectedRest:         []byte("\r"),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("finger/1\r"),
+			ExpectedResult: []byte("finger/1"),
+			ExpectedRest:      []byte("\r"),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("finger\r"),
+			ExpectedResult: []byte("finger"),
+			ExpectedRest:       []byte("\r"),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("1.22.333\r"),
+			ExpectedResult: []byte("1.22.333"),
+			ExpectedRest:        []byte("\r"),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("v12.23.34\r"),
+			ExpectedResult: []byte("v12.23.34"),
+			ExpectedRest:       []byte("\r"),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte(`()<>@,;:\"/[]?={} `),
+			ExpectedResult: []byte(`()<>@,;:\"/[]?={}`),
+			ExpectedRest:                    []byte(` `),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("😈\r"),
+			ExpectedResult: []byte(`😈`),
+			ExpectedRest:     []byte("\r"),
+			ExpectedOK: true,
+		},
+
+
+
+		{
+			Value:          []byte("HTTP/1.1\n"),
+			ExpectedResult: []byte("HTTP/1.1"),
+			ExpectedRest:          []byte("\n"),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("HTTP/1\n"),
+			ExpectedResult: []byte("HTTP/1"),
+			ExpectedRest:         []byte("\n"),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("finger/1\n"),
+			ExpectedResult: []byte("finger/1"),
+			ExpectedRest:      []byte("\n"),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("finger\n"),
+			ExpectedResult: []byte("finger"),
+			ExpectedRest:       []byte("\n"),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("1.22.333\n"),
+			ExpectedResult: []byte("1.22.333"),
+			ExpectedRest:        []byte("\n"),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("v12.23.34\n"),
+			ExpectedResult: []byte("v12.23.34"),
+			ExpectedRest:       []byte("\n"),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte(`()<>@,;:\"/[]?={} `),
+			ExpectedResult: []byte(`()<>@,;:\"/[]?={}`),
+			ExpectedRest:                    []byte(` `),
+			ExpectedOK: true,
+		},
+		{
+			Value:          []byte("😈\n"),
+			ExpectedResult: []byte(`😈`),
+			ExpectedRest:     []byte("\n"),
+			ExpectedOK: true,
+		},
+	}
+
+	for testNumber, test := range tests {
+
+		actualResult, actualRest, actualOK := version.BytesTolerant(test.Value)
+
+		{
+			expected := test.ExpectedOK
+			actual   := actualOK
+
+			if expected != actual {
+				t.Errorf("For test #%d, the actual ok-result is not what was expected." , testNumber)
+				t.Logf("EXPECTED: %t", expected)
+				t.Logf("ACTUAL:   %t", actual)
+				t.Logf("VALUE: %q (%#v)", test.Value, test.Value)
+				continue
+			}
+		}
+
+		{
+			expected := test.ExpectedResult
+			actual   := actualResult
+
+			if !bytes.Equal(expected, actual) {
+				t.Errorf("For test #%d, the actual result is not what was expected." , testNumber)
+				t.Logf("EXPECTED: %q (%#v)", expected, expected)
+				t.Logf("ACTUAL:   %q (%#v)", actual, actual)
+				t.Logf("VALUE: %q (%#v)", test.Value, test.Value)
+				continue
+			}
+		}
+
+		{
+			expected := test.ExpectedRest
+			actual   := actualRest
+
+			if !bytes.Equal(expected, actual) {
+				t.Errorf("For test #%d, the actual rest is not what was expected." , testNumber)
+				t.Logf("EXPECTED: %q (%#v)", expected, expected)
+				t.Logf("ACTUAL:   %q (%#v)", actual, actual)
+				t.Logf("VALUE: %q (%#v)", test.Value, test.Value)
+				continue
+			}
+		}
+	}
+}