Mo. Rev. Stat. § 448.040
Simultaneously with the recording of the declaration there shall be recorded a plat as defined in section 448.010, which plat shall be made by a registered Missouri land surveyor and shall set forth all angular and linear data along the exterior boundaries of the parcel; the linear measurements and location, with reference to the exterior boundaries, of the building or buildings located or to be located on the parcel; and the elevations or proposed elevations at, above, or below official datum of the finished or unfinished interior surfaces of the floors and ceilings and the linear measurements of the actual or proposed finished or unfinished interior surfaces of the perimeter walls, and lateral extensions thereof, of every unit or proposed unit in the building or buildings, and the locations or proposed locations of such wall surfaces with respect to the exterior boundaries of the parcel projected vertically upward. Every such unit shall be identified on the plat by a distinguishing number or other symbol. If the plat is recorded as a separate document, a statement shall appear thereon identifying it with the declaration provided for in section 448.030, which statement shall be signed and acknowledged by the same persons executing the declaration. An amendment or amendments to a plat may be recorded by the developer to include an additional parcel or parcels and additional units or to delete any parcel or parcels and reduce the number of units or to reflect accurately any changes in the locations, elevations, measurements or dimensions of any prior recorded plat, provided all the unit owners have consented thereto.
§ 448.040, RSMo