title: Should we use _In_ instead of __in?
body: <p>I read sal.h, which is in VS2010, today.<br>
  I was a little surprised.</p>
  
  <pre><code>// This section contains the deprecated annotations
  |------------|------------|---------|--------|----------|----------|---------------|
  |   Level    |   Usage    |  Size   | Output | NullTerm | Optional |  Parameters   |
  |------------|------------|---------|--------|----------|----------|---------------|
  | &lt;&gt;         | &lt;&gt;         | &lt;&gt;      | &lt;&gt;     | _z       | &lt;&gt;       | &lt;&gt;            |
  | _deref     | _in        | _ecount | _full  | _nz      | _opt     | (size)        |
  | _deref_opt | _out       | _bcount | _part  |          |          | (size,length) |
  |            | _inout     |         |        |          |          |               |
  |            |            |         |        |          |          |               |
  |------------|------------|---------|--------|----------|----------|---------------|
  </code></pre>
  
  <p>I always used these annotations.<br>
  I can't believe that they are deprecated. Is it true?<br>
  If so, why?<br>
  Should we use following annotations from now on? -It's not familiar to me :(</p>
  
  <pre><code>|--------------|----------|----------------|-----------------------------|
  |   Usage      | Nullness | ZeroTerminated |  Extent                     |
  |--------------|----------|----------------|-----------------------------|
  | _In_         | &lt;&gt;       | &lt;&gt;             | &lt;&gt;                          |
  | _Out_        | opt_     | z_             | [byte]cap_[c_|x_]( size )   |
  | _Inout_      |          |                | [byte]count_[c_|x_]( size ) |
  | _Deref_out_  |          |                | ptrdiff_cap_( ptr )         |
  |--------------|          |                | ptrdiff_count_( ptr )       |
  | _Ret_        |          |                |                             |
  | _Deref_ret_  |          |                |                             |
  |--------------|          |                |                             |
  | _Pre_        |          |                |                             |
  | _Post_       |          |                |                             |
  | _Deref_pre_  |          |                |                             |
  | _Deref_post_ |          |                |                             |
  |--------------|----------|----------------|-----------------------------|
  </code></pre>
  
  <p>By the way, SAL tag doesn't exist in SO.<br>
  Please make it, if you could.</p>