title: What are PHP flags in function arguments?
body: <p>I noticed that some functions in PHP use <em>flags</em> as arguments. What makes them unique instead of plain string arguments? I'm asking since I want to use them on my own custom functions but am curious as to what the process is for doing so.</p>
  
  <p><strong>Edit:</strong> TO summarize, when is it best to create a custom function with flags and when is it <em>not</em>?</p>