${{\mathit N}}$ BARYONS ($\mathit S$ = 0, $\mathit I$ = 1/2)

${{\mathit p}}$, ${{\mathit N}^{+}}$ = ${\mathit {\mathit u}}$ ${\mathit {\mathit u}}$ ${\mathit {\mathit d}}$; ${{\mathit n}}$, ${{\mathit N}^{0}}$ = ${\mathit {\mathit u}}$ ${\mathit {\mathit d}}$ ${\mathit {\mathit d}}$
 
****   Existence is certain, and properties are at least fairly explored.
***   Existence ranges from very likely to certain, but further confirmation is desirable and/or quantum numbers, branching fractions, etc. are not well determined.
**   Evidence of existence is only fair.
*   Evidence of existence is poor.