Found the following HTML validation problems:
abc.html:19:1 (abc.Rd:13): Warning: <h2> attribute "id" has invalid value "approximate Bayesian computation"
accumulators.html:19:1 (accumulators.Rd:6): Warning: <h2> attribute "id" has invalid value "accumulator variables"
bake.html:19:1 (bake.Rd:8): Warning: <h2> attribute "id" has invalid value "reproducibility tools"
basic_components.html:19:1 (basic_components.Rd:5): Warning: <h2> attribute "id" has invalid value "basic components"
basic_probes.html:19:1 (basic_probes.Rd:15): Warning: <h2> attribute "id" has invalid value "basic probes"
childhood.html:19:1 (childhood.Rd:9): Warning: <h2> attribute "id" has invalid value "childhood disease data"
dmeasure_spec.html:19:1 (dmeasure_spec.Rd:5): Warning: <h2> attribute "id" has invalid value "dmeasure specification"
dprocess_spec.html:19:1 (dprocess_spec.Rd:5): Warning: <h2> attribute "id" has invalid value "dprocess specification"
elementary_algorithms.html:19:1 (elementary_algorithms.Rd:5): Warning: <h2> attribute "id" has invalid value "elementary algorithms"
emeasure_spec.html:19:1 (emeasure_spec.Rd:5): Warning: <h2> attribute "id" has invalid value "emeasure specification"
estimation_algorithms.html:19:1 (estimation_algorithms.Rd:5): Warning: <h2> attribute "id" has invalid value "estimation algorithms"
nlf.html:19:1 (nlf.Rd:12): Warning: <h2> attribute "id" has invalid value "nonlinear forecasting"
parameter_trans.html:19:1 (parameter_trans.Rd:16): Warning: <h2> attribute "id" has invalid value "parameter transformations"
pomp_examp.html:19:1 (pomp_examp.Rd:6): Warning: <h2> attribute "id" has invalid value "pomp examples"
prior_spec.html:19:1 (prior_spec.Rd:5): Warning: <h2> attribute "id" has invalid value "prior specification"
probe_match.html:19:1 (probe_match.Rd:13): Warning: <h2> attribute "id" has invalid value "probe matching"
rinit_spec.html:19:1 (rinit_spec.Rd:5): Warning: <h2> attribute "id" has invalid value "rinit specification"
rmeasure_spec.html:19:1 (rmeasure_spec.Rd:5): Warning: <h2> attribute "id" has invalid value "rmeasure specification"
rprocess_spec.html:19:1 (rprocess_spec.Rd:11): Warning: <h2> attribute "id" has invalid value "rprocess specification"
sir.html:19:1 (sir.Rd:8): Warning: <h2> attribute "id" has invalid value "SIR models"
skeleton_spec.html:19:1 (skeleton_spec.Rd:8): Warning: <h2> attribute "id" has invalid value "skeleton specification"
spect_match.html:19:1 (spect_match.Rd:13): Warning: <h2> attribute "id" has invalid value "spectrum matching"
traj_match.html:19:1 (traj_match.Rd:12): Warning: <h2> attribute "id" has invalid value "trajectory matching"
vmeasure_spec.html:19:1 (vmeasure_spec.Rd:5): Warning: <h2> attribute "id" has invalid value "vmeasure specification"