(a) Unless issued a valid server training certificate between July 1, 2012 and July 1, 2015 by a certified Beverage Alcohol Sellers and Servers Education and Training (BASSET) trainer, all alcohol servers in Cook County are required to obtain and complete training in basic responsible alcohol service as outlined in 77 Ill. Adm. Code 3500, as those provisions exist on July 1, 2015 (the effective date of Public Act 98-939), by July 1, 2015 or within 120 days after the alcohol server begins his or her employment, whichever is later. All alcohol servers in a county, other than Cook County, with a population of 200,000 inhabitants or more are required to obtain and complete training in basic responsible alcohol service as outlined in 77 Ill. Adm. Code 3500, as those provisions exist on July 1, 2015 (the effective date of Public Act 98-939), by July 1, 2016 or within 120 days after the alcohol server begins his or her employment, whichever is later. All alcohol servers in a county with a population of more than 30,000 inhabitants and less than 200,000 inhabitants are required to obtain and complete training in basic responsible alcohol service as outlined in 77 Ill. Adm. Code 3500, as those provisions exist on July 1, 2015 (the effective date of Public Act 98-939), by July 1, 2017 or within 120 days after the alcohol server begins his or her employment, whichever is later. All alcohol servers in counties with a population of 30,000 inhabitants or less are required to obtain and complete training in basic responsible alcohol service as outlined in 77 Ill. Adm. Code 3500, as those provisions exist on July 1, 2015 (the effective date of Public Act 98-939), by July 1, 2018 or within 120 days after the alcohol server begins his or her employment, whichever is later. There is no limit to the amount of times a server may take the training. A certificate of training belongs to the server, and a server may transfer a certificate of training to a different employer, but shall not transfer a certificate of training to another server. Proof that an alcohol server has been trained must be available upon reasonable request by State law enforcement officials. For the purpose of this Section, "alcohol servers" means persons who sell or serve open containers of alcoholic beverages at retail, anyone who delivers mixed drinks under Section 6-28.8, and anyone whose job description entails the checking of identification for the purchase of open containers of alcoholic beverages at retail or for entry into the licensed premises. The definition does not include (i) a distributor or importing distributor conducting product sampling as authorized in Section 6-31 of this Act or a registered tasting representative, as provided in 11 Ill. Adm. Code 100.40, conducting a tasting, as defined in 11 Ill. Adm. Code 100.10; (ii) a volunteer serving alcoholic beverages at a charitable function; or (iii) an instructor engaged in training or educating on the proper technique for using a system that dispenses alcoholic beverages.