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+`'_` lifetime name or `&T` without an explicit lifetime name has been used
+on illegal place.
+
+Erroneous code example:
+
+```compile_fail,E0106,E0637
+fn underscore_lifetime<'_>(str1: &'_ str, str2: &'_ str) -> &'_ str {
+                     //^^ `'_` is a reserved lifetime name
+    if str1.len() > str2.len() {
+        str1
+    } else {
+        str2
+    }
+}
+
+fn and_without_explicit_lifetime<T>()
+where
+    T: Into<&u32>,
+          //^ `&` without an explicit lifetime name
+{
+}
+```
+
+First, `'_` cannot be used as a lifetime identifier in some places
+because it is a reserved for the anonymous lifetime. Second, `&T`
+without an explicit lifetime name cannot also be used in some places.
+To fix them, use a lowercase letter such as `'a`, or a series
+of lowercase letters such as `'foo`. For more information about lifetime
+identifier, see [the book][bk-no]. For more information on using
+the anonymous lifetime in Rust 2018, see [the Rust 2018 blog post][blog-al].
+
+Corrected example:
+
+```
+fn underscore_lifetime<'a>(str1: &'a str, str2: &'a str) -> &'a str {
+    if str1.len() > str2.len() {
+        str1
+    } else {
+        str2
+    }
+}
+
+fn and_without_explicit_lifetime<'foo, T>()
+where
+    T: Into<&'foo u32>,
+{
+}
+```
+
+[bk-no]: https://doc.rust-lang.org/book/appendix-02-operators.html#non-operator-symbols
+[blog-al]: https://blog.rust-lang.org/2018/12/06/Rust-1.31-and-rust-2018.html#more-lifetime-elision-rules