This recommended practice establishes guidance for design, system verification, and application guidelines of solid expandable systems for the oil and gas industries. This document is not to be used as a specification for purchasing equipment; it is intended for consideration by users for well applications and design of solid expandable systems. Expandable systems will include drilling liners, hangers, connections, receivers, and launchers for downhole use as defined herein. Only permanently installed equipment/components are covered by this recommended practice. Slotted liners and tools used for the expansion of the tubular goods (such as, but not limited to, implementation tools, pumps, jacks, and expansion tools) are not addressed by this recommended practice. The goals of this recommended practice are to: 1) establish common terms and means that can be used by manufacturers and end users, 2) educate end users and manufacturers, 3) ensure that users, suppliers, and manufacturers understand and can identify the critical aspects of the technology, 4) accelerate the technology and expand the user base, 5) institute a uniform evaluation process, and 6) understand the reliability of the technology. Users should be aware that requirements outlined in this document may be needed for individual applications. This document is not intended to inhibit a supplier/manufacturer from offering, or the user/purchaser from accepting, alternative equipment or engineering solutions. This may be particularly applicable where there is innovative or developing technology.