An mspace empty element represents a blank space of any desired size, as set by its attributes. It can also be used to make linebreaking suggestions to a visual renderer. MathML Fundamentals
<math> <mspace linebreak="newline" indentalign="center"></mspace> <mtext style="border:1px;" mathsize="50">Mspace - width, height, depth, indentalign</mtext> <mspace linebreak="newline" indentalign="center"></mspace> <mrow style="border:1px"> <mtext>aaa</mtext> <mspace style="border:1px" width="50" height="10"></mspace> <msqrt style="border:1px"> <mrow style="border:1px"> <mi style="border:1px">aagg</mi> <mo>+</mo> <mspace style="border:1px" width="10" height="100"></mspace> <mi style="border:1px">ABC</mi> <mspace style="border:1px" width="10" height="0" depth="20"></mspace> <mi style="border:1px">ABC</mi> </mrow> </msqrt> </mrow> </math>