Polish "Clarify edge case docs on ConditionalOnClass"

Closes gh-8185

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/condition/ConditionalOnClass.java

 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -36,14 +36,11 @@ import org.springframework.context.annotation.Conditional;
 public @interface ConditionalOnClass {
 
 	/**
-	 * <p>
-	 * The classes that must be present. Since this annotation parsed by loading class
-	 * bytecode it is safe to specify classes here that may ultimately not be on the
+	 * The classes that must be present. Since this annotation is parsed by loading class
+	 * bytecode, it is safe to specify classes here that may ultimately not be on the
 	 * classpath, only if this annotation is directly on the affected component and
-	 * <b>not</b> if this annotation is used as a composed, meta-annotation. If this
-	 * is used as a meta annotation and the given class is not available at runtime
-	 * then this {@link @Conditional} will effectively be ignored. In order to use
-	 * this annotation as a meta-annotation, only use the {@link #name} attribute.
+	 * <b>not</b> if this annotation is used as a composed, meta-annotation. In order to
+	 * use this annotation as a meta-annotation, only use the {@link #name} attribute.
 	 * @return the classes that must be present
 	 */
 	Class<?>[] value() default {};

spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc

@@ -5839,16 +5839,18 @@ code by annotating `@Configuration` classes or individual `@Bean` methods.
 [[boot-features-class-conditions]]
 ==== Class conditions
 The `@ConditionalOnClass` and `@ConditionalOnMissingClass` annotations allows
-configuration to be included based on the presence or absence of specific classes.
-If you are using the `@ConditionalOnClass` annotation directly on the class you are conditionally
-registering, you can actually use the `value` attribute to refer to the real class,
-even though that class might not actually appear on the running application classpath.
-This is due to the fact that annotation metadata directly on a class is parsed
-using http://asm.ow2.org/[ASM]. You can also use the `name` attribute if you prefer to
-specify the class name using a `String` value, which is required if you are using
-`@ConditionalOnClass` or `@ConditionalOnMissingClass` as apart of a meta-annotation to
-compose your own composed annotations or in an `@Bean` method as neither of these cases
-are handled by ASM.
+configuration to be included based on the presence or absence of specific classes. Due to
+the fact that annotation metadata is parsed using http://asm.ow2.org/[ASM] you can
+actually use the `value` attribute to refer to the real class, even though that class
+might not actually appear on the running application classpath. You can also use the
+`name` attribute if you prefer to specify the class name using a `String` value.
+
+[TIP]
+====
+If you are using `@ConditionalOnClass` or `@ConditionalOnMissingClass` as apart of a
+meta-annotation to compose your own composed annotations you must use `name` as referring
+to the class in such a case is not handled.
+====