If you have no Invariant Sections, write with no Invariant Sections” instead of saying which ones are invariant. If you have no Front-Cover Texts, write no Front-Cover Texts” instead of Front-Cover Texts being LIST”; likewise for Back-Cover Texts.If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software.