Found the following HTML validation problems:
data.TEODP2017.html:19:1 (data.TEODP2017.Rd:7): Warning: <h2> attribute "id" has invalid value "TEO at DP 2017"
data.Tidal.html:19:1 (data.Tidal.Rd:14): Warning: <h2> attribute "id" has invalid value "Tidal Data"
data.Wave.html:19:1 (data.Wave.Rd:7): Warning: <h2> attribute "id" has invalid value "Waves Data"
data.taubd.html:19:1 (data.taubd.Rd:9): Warning: <h2> attribute "id" has invalid value "tau and bd"
functions.ac.plot.phasors.html:19:1 (functions.ac.plot.phasors.Rd:21): Warning: <h2> attribute "id" has invalid value "AC waves and plots"
functions.ac.power.html:19:1 (functions.ac.power.Rd:13): Warning: <h2> attribute "id" has invalid value "AC power"
functions.dc.power.html:19:1 (functions.dc.power.Rd:15): Warning: <h2> attribute "id" has invalid value "DC circuits"
functions.hydrology.html:19:1 (functions.hydrology.Rd:11): Warning: <h2> attribute "id" has invalid value "Hydro Power Hydrology"
functions.hydropower.html:19:1 (functions.hydropower.Rd:13): Warning: <h2> attribute "id" has invalid value "Hydro Power"
functions.hydrotidalpower.html:19:1 (functions.hydrotidalpower.Rd:11): Warning: <h2> attribute "id" has invalid value "Tidal Power"
functions.hydrowavepower.html:19:1 (functions.hydrowavepower.Rd:12): Warning: <h2> attribute "id" has invalid value "Wave Power"
functions.magnetic.circuits.html:19:1 (functions.magnetic.circuits.Rd:8): Warning: <h2> attribute "id" has invalid value "magnetic circuits"
functions.panels.plot.html:19:1 (functions.panels.plot.Rd:7): Warning: <h2> attribute "id" has invalid value "panels plots"
functions.power.electronics.html:19:1 (functions.power.electronics.Rd:8): Warning: <h2> attribute "id" has invalid value "AC-DC power electronics"
functions.solarpower.html:19:1 (functions.solarpower.Rd:21): Warning: <h2> attribute "id" has invalid value "Solar Power"
functions.thermo.paths.html:19:1 (functions.thermo.paths.Rd:24): Warning: <h2> attribute "id" has invalid value "thermo paths"
functions.windpower.html:19:1 (functions.windpower.Rd:21): Warning: <h2> attribute "id" has invalid value "Wind Power"