... //Assign a unique id to this tag. $tagid = uniqid(); //Remember the mapping of unique id to tag name. $tags[$tagid] = trim($token[1], '@ '); }}//Join the array with unique id with ... elements can occur more than once per tag and must be appended to the tag. Because tags can occur multiple times, you cannot just append the text. Instead, you need to assign a tag a unique ID to differentiate ... will be ignored. This can help you to avoid implementing complex interfaces, and it allows for more flexible authoring.For example, suppose you had the interface shown in Listing 7-2.Listing...