networking - Interpreting CSN.1 notation from 3GPP standards 44.060 -

If someone can explain in clear English then the following CSN.1 means I would be very grateful. It has been taken in section 11.2.6 for EGPRS2 packet downex ACK / NAK type 2 information element.

  {0 | 1 & lt; EPD A / N Extension Type 2 Length: Bit (8) & gt; & Lt; Bit (wal (EPD A / N extension length) + 1) & amp; {& Lt; EPD A / N Extension Info Type 2 & gt; ! {Bit ** = & lt; Any string & gt; }} & Gt; }    
 element described as a variable length set of EPD A / N extension type 2 information elements.  
 Which means that I understand that the element is conditional if a 1 is present in the stream then after 8 bits of EPD A / N extension type 2 length, after a slight strings of this length + 1, But  & amp; {& Lt; EPD A / N Extension Info Type 2 & gt; ?  
 My impression is that it has been clearly stated that this bit string is an EPD A / N extension information type 2 notification element is it correct?   
 
 
 I point you to monitor intersection and error signals.  
 Intersection, & amp; nbsp;, to ensure that & lt; EPD A / N Extension Info Type 2 & gt; Element bitstrings bit (w.e.p.d. / n extension length) fits on +1, and & lt; EPD A / N extension information type2 & gt; element for bitstrings length if it does not limit the length  
 The error signal,!, Indicates that if the   
  
 A / N Extension Info Type 2> Fit on element bitstrings That is, an error should be flagged and the bitstrings should be discarded.