London - For the first time, an advertisement for the post of Black Rod - the House of Lords official who ceremonially summons MPs from the Commons to attend the Queen's Speech - appeared in the national press yesterday. The advert for the position, with an annual salary of up to £101,250, has been placed in yesterday's edition of the Times and in the Guardian tomorrow. Traditionally the post has always gone to a former senior military man and was for many years informally rotated between the three Services.