(

a) The board may impose a retail transactions and use tax ordinance applicable to the entire district in accordance with

Part 1.6 (commencing with

Section 7251) of Division of the Revenue and Taxation Code if the electors voting on the measure vote to approve its imposition at the election described in

Section in accordance with this title and

Part 1.6 (commencing with

Section 7251) of Division of the Revenue and Taxation Code. (

b) The board may impose a retail transactions and use tax pursuant to subdivision (

a) that, in combination with all taxes imposed in accordance with

Part 1.6 (commencing with

Section 7251) of Division of the Revenue and Taxation Code, exceeds the limit established in

Section 7251.1 of the Revenue and Taxation Code. (

c) The board, in the ordinance, shall do all of the following:

(1) State the nature of the tax to be imposed.

(2) Provide the tax rates as follows: (

A) Except as provided in subparagraph (B), the tax rate shall be one-half of percent in each county comprising the district. (

B) The tax rate in the City and County of San Francisco shall be percent.

(3) Specify the period during which the tax will be imposed, which shall be years beginning on the date the ordinance becomes operative.

(4) Specify the purposes for which the revenue derived from the tax will be used, consistent with

Chapter 3 (commencing with

Section 67750). (

d) Notwithstanding

Section 7251.1 of the Revenue and Taxation Code, the tax rate authorized pursuant to this

section shall not be considered for purposes of the combined rate limit established by

Section 7251.1 of the Revenue and Taxation Code.