Found the following HTML validation problems:
arcops.html:19:1 (arcops.Rd:8): Warning: <h2> attribute "id" has invalid value "arc operations"
blacklist.html:19:1 (blacklist.Rd:7): Warning: <h2> attribute "id" has invalid value "utilities for whitelists and blacklists"
bn.class.html:19:1 (bn.class.Rd:4): Warning: <h2> attribute "id" has invalid value "bn class"
bn.fit.class.html:19:1 (bn.fit.class.Rd:6): Warning: <h2> attribute "id" has invalid value "bn.fit class"
bn.fit.methods.html:19:1 (bn.fit.methods.Rd:23): Warning: <h2> attribute "id" has invalid value "bn.fit utilities"
bn.fit.plots.html:19:1 (bn.fit.plots.Rd:8): Warning: <h2> attribute "id" has invalid value "bn.fit plots"
bn.kcv.class.html:19:1 (bn.kcv.class.Rd:6): Warning: <h2> attribute "id" has invalid value "bn.kcv class"
bn.strength-class.html:19:1 (bn.strength-class.Rd:5): Warning: <h2> attribute "id" has invalid value "bn.strength class"
constraint.html:19:1 (constraint.Rd:12): Warning: <h2> attribute "id" has invalid value "constraint-based algorithms"
count.graphs.html:19:1 (count.graphs.Rd:4): Warning: <h2> attribute "id" has invalid value "graph enumeration"
foreign.html:19:1 (foreign.Rd:9): Warning: <h2> attribute "id" has invalid value "foreign files utilities"
gRain.html:19:1 (gRain.Rd:9): Warning: <h2> attribute "id" has invalid value "gRain integration"
graph.html:19:1 (graph.Rd:14): Warning: <h2> attribute "id" has invalid value "graph utilities"
graphgen.html:19:1 (graphgen.Rd:5): Warning: <h2> attribute "id" has invalid value "graph generation utilities"
graphpkg.html:19:1 (graphpkg.Rd:11): Warning: <h2> attribute "id" has invalid value "graph integration"
hc.html:19:1 (hc.Rd:5): Warning: <h2> attribute "id" has invalid value "score-based algorithms"
hybrid.html:19:1 (hybrid.Rd:6): Warning: <h2> attribute "id" has invalid value "hybrid algorithms"
igraphpkg.html:19:1 (igraphpkg.Rd:7): Warning: <h2> attribute "id" has invalid value "igraph integration"
learn.html:19:1 (learn.Rd:5): Warning: <h2> attribute "id" has invalid value "single-node local discovery"
mb.html:19:1 (mb.Rd:41): Warning: <h2> attribute "id" has invalid value "misc utilities"
mi.matrix.html:19:1 (mi.matrix.Rd:5): Warning: <h2> attribute "id" has invalid value "local discovery algorithms"
modelstring.html:19:1 (modelstring.Rd:9): Warning: <h2> attribute "id" has invalid value "model string utilities"
mvnorm.html:19:1 (mvnorm.Rd:4): Warning: <h2> attribute "id" has invalid value "multivariate normal distribution"
nodeops.html:19:1 (nodeops.Rd:11): Warning: <h2> attribute "id" has invalid value "node operations"
ordering.html:19:1 (ordering.Rd:4): Warning: <h2> attribute "id" has invalid value "node ordering utilities"
pcalg.html:19:1 (pcalg.Rd:4): Warning: <h2> attribute "id" has invalid value "pcalg integration"
preprocessing.html:19:1 (preprocessing.Rd:4): Warning: <h2> attribute "id" has invalid value "data preprocessing"
rocrpkg.html:19:1 (rocrpkg.Rd:5): Warning: <h2> attribute "id" has invalid value "ROCR integration"
statspkg.html:19:1 (statspkg.Rd:7): Warning: <h2> attribute "id" has invalid value "lm integration"
test.counter.html:19:1 (test.counter.Rd:5): Warning: <h2> attribute "id" has invalid value "test counter"