1. no blank lines between `http' addresses --- add

                   group containing     group containing
posting content      `http://hoge'        `http://foo'         new address

 +------------        * http://aa               
 |http://hoge         * http://bb         * http://aaa
 |http://foo     =>   * http://cc    +    * http://bbb    +   * http://baa
 |http://baa          * http://dd         * http://foo
 |                    * http://hoge

                         grouping
                      all addresses

                      * http://aa
                      * http://aaa
                      * http://bb
                      * http://bbb
                 =>   * http://cc
                      * http://dd
                      * http://hoge
                      * http://foo
                      * http://baa


2. addresses separated by blank lines --- divide

posting content         grouping            grouping            grouping

 +------------
 |http://hoge
 |http://hoge2
 |                    * http://hoge       * http://foo
 |http://foo     =>   * http://hoge2  ,   * http://foo2   ,   * http://baa
 |http://foo2
 |
 |http://baa
 |


3. addresses containg `http://tako3.com/deleteme' --- delete

if you missed:

posting content          grouping

 +------------
 |http://hoge         * http://hoge
 |http://hoge2   =>   * http://hoge2
 |http://hog3         * http://hog3 -- ow!
 |

you can notice to admin:

revising content               revised grouping         grouping (deleteme)

 +------------
 |http://hoge                   * http://hoge       * http://hog3
 |http://hoge2         =>       * http://hoge2      * http://tako3.com/deleteme
 |http://hoge3                  * http://hoge3   ,
 |
 |http://hog3
 |http://tako3.com/deleteme
 |

admin will catch and delete