The legislative body of a municipality may initiate a proposed amendment to the municipal charter by a resolution that, except as otherwise provided in this subtitle, is adopted in the same manner as other resolutions in the municipality by a majority of all the individuals elected to the legislative body. Before adopting a resolution initiated by the legislative body of a municipality that proposes an amendment to the municipal charter, the legislative body shall: hold a public hearing on the proposed amendment; and give at least 21 days’ advance notice of the public hearing. The chief executive officer of the municipality shall give notice of the resolution that proposes an amendment to the municipal charter by: posting an exact copy of the resolution at the main municipal building or other public place for the 40 days after the resolution is adopted; and publishing a fair summary of the proposed amendment in a newspaper of general circulation in the municipality: at least four times; at weekly intervals; and within the 40 days after the resolution is adopted; or publishing a fair summary of the proposed amendment in a newspaper of general circulation in the municipality at least once; and delivering a copy of a fair summary of the proposed charter amendment either by hand or by mail once to every residence in the municipality. The delivery required under paragraph (1)(ii)2B of this subsection may be accomplished by including a fair summary of the proposed charter amendment in a printed newsletter or any other regular municipal publication. The municipality delivering a copy of a fair summary under paragraph (1)(ii)2B of this subsection shall: maintain a record of or a copy of the receipt for the delivery under the records retention and document disposal schedule of the municipality; and make the record or copy available to the general public in accordance with the Maryland Public Information Act. Unless a petition meeting the requirements of subsection (d) of this section is presented to the legislative body of a municipality on or before the 40th day after the legislative body adopts a charter amendment resolution, the amendment shall take effect as a part of the municipal charter on the 50th day after the resolution is adopted. A petition for a referendum on a proposed charter amendment shall: be signed by at least 20% of the qualified voters for the municipal general election; and request that the proposed amendment be submitted to referendum of the qualified voters of the municipality. Each individual signing the petition shall indicate on the petition the individual’s name and residence address. The petition shall be delivered to the legislative body of the municipality by: presentment; or certified mail, return receipt requested. On receiving the petition, the legislative body shall verify that each individual who signed the petition is a qualified voter for the municipal general election. The petition has no effect if it is signed by less than 20% of the qualified voters for the municipal general election. If the petition complies with this section, the legislative body shall specify by resolution adopted in accordance with its normal legislative procedure: the day and hours for the referendum; and the exact text that is to be placed on the ballot. The legislative body may schedule the referendum for the next regular municipal general election or at a special election. If the legislative body schedules a special election, it shall be held not less than 40 days or more than 60 days after the resolution scheduling the referendum is adopted.