a + after a tag -> may have 1 or more
a * after a tag -> may have 0 or more
a ? after a tag -> may have 0 or 1 entry for that element



<companyInfo>
    <companyName> groupname </>
    <products>
       <!-- books and products may appear in any order -->
       <book>
          <isbn> string(10) </isbn>
          <title> string(arbitrary length) </>
          <year> number(4) </> ?
          <category> string(50); first one is the main category </> +
          <author> <fn> (incl. middle i.) string </>?   <ln> string </>   </> +
          <publisher>string </>
          <keyword> string (arbitrary length) </>*
          <price> 999.99  </>
          <discountPrice> 999.99 (discounted price, = ACTUAL SELLING PRICE AFTER DISCOUNT) </>
          <quantity> integer </> (amount available, sum over all warehouse)
          <description> optional.... </> ?
       </book>


       <book> ............more books........... </book>


       <music>
          <id> string(10) </>
          <albumName> string </>
          <genre> like category </>
          <artist> string </artist>
          <recordingCompany> recording company </>
          <price> same as book </>
          <discount> same as book </>
          <quantity> same as book </>
          <description> same as book </>
       </music>


       <music> ........ more music........... </>
    </products>


    <shipping> shipping vendors that ships stuff for your company
       <vendor>
          <name> name of this vendor (UPS, FEDEX etc.) </>
          <url> string </> ?
          <toll-free> string </>
          <method id = "a number to represent this shipping method">
               <option> standard, next day, overnight, air, missile,
                              teleport.... etc. anything </option>
               <price>
                      <flat> 99.99 </> ?
                      <perUnit> 99.99 </> ?
                      <perPound> 99.99 </> ?
               </price>
                     <restrictions>
                        <maximumWeight> max weight allowed. </> ?
			<maximumItems> max item allowed. </> ?
                        <cities> cities of destination that can be selected </> *
                     </restrictions>
           </method> +
       </vendor>+



    </shipping>
</companyInfo>