How Does Magento 2 Generate the admin-icons Font Files?

Quite often everything inside bra or ket is just a label. In this particular case the meaning of $|λ,m_l⟩$ is "a state with the square of the angular momentum being equal to $λ$ (in atomic units, where $\hbar=1$) and with the projection of the angular momentum in some direction ($z$-axis conventionally) being equal to $m_l$".

That is, $|λ,m_l⟩$ state is the simultaneous eigenstate of both $\hat{L}^2$ and $\hat{L}_z$, i.e. it is an eigenstate of $\hat{L}^2$ (with eigenvalue $λ \hbar^2$, or just $λ$ in atomic units) and at the same time it is an eigenstate of $\hat{L}_z$ (with eigenvalue $m_l \hbar$, or just $m_l$ in atomic units). Such simultaneous eigenstates exist because the corresponding operators commute $[\hat{L}^2, \hat{L}_z] = 0$, or, in other words, because the corresponding observables are compatible.

All sectional command globally set the internal conditional \if@nobreak to true. This conditional is reset to false as soon as a paragraph is started. However, floats would change it only if really typeset at the spot. The rationale is that a float appearing immediately after a sectional title counts as the first paragraph after the title.

You probably will be satisfied with

\makeatletter
\newenvironment{myenv}{%
  % Some detection mechanism
  % that sets RightAfterASectioningCommand
  % to true or false
  % ...
  \if@nobreak
    Right after a sectioning command
  \else
    Not right after a sectioning command
  \fi
  }{}
\makeatother

If you import Priority as "1", that should set the phone number being imported as the highest-priority number.

If Priority is not included, the phone number will be appended to the current record (if one already exists for the contact).