  We report identification of the radio loud narrow-line quasar SDSS
J172206.03+565451.6 which we found in the course of a search for radio loud
narrow-line Active Galactic Nuclei (AGN). SDSSJ172206.03+565451.6 is only the
~4th securely identified radio loud narrow-line quasar and the second-most
radio loudest with a radio index R_1.4 ~ 100-700. Its black hole mass, M_BH =
(2-3) 10^7 M_sun, is unusually small given its radio loudness, and the
combination of mass and radio index puts SDSSJ172206.03+565451.6 in a scarcely
populated region of M_BH-R diagrams. SDSSJ172206.03+565451.6 is a classical
Narrow-Line Seyfert1-type object with FWHM_Hbeta = 1490 km/s, an intensity
ratio of [OIII]/Hbeta = 0.7 and FeII emission complexes with FeII4570/Hbeta =
0.7. The ionization parameter of its narrow-line region, estimated from the
line ratio [OII]/[OIII], is similar to Seyferts and its high ratio of
[NeV]/[NeIII] indicates a strong EUV to soft-X-ray excess. We advertise the
combined usage of [OII]/[OIII] and [NeV]/[NeIII] diagrams as a useful
diagnostic tool to estimate ionization parameters and to constrain the EUV
continuum shape relatively independent from other parameters.
