The ms element is used to represent "string literals" in expressions meant to be interpreted by computer algebra systems or other systems containing "programming languages". By default, string literals are displayed surrounded by double quotes, with no extra spacing added around the string. MathML Fundamentals
<math> <mspace linebreak="newline" indentalign="center"></mspace> <mtext style="border:1px;">String Literal ms</mtext> <mspace linebreak="newline" indentalign="center"></mspace> <mtext>Theorem 1:</mtext> <mspace linebreak="newline" indentalign="center"></mspace> <ms>Theorem 1:</ms> <mspace linebreak="newline" indentalign="center"></mspace> <ms rquote="'">Right change</ms> <mspace linebreak="newline" indentalign="center"></mspace> <ms lquote="'">Left change</ms> </math>