Why "A symbol occurs in more than one context" in text analysis functions?

Recently noticed, that some new text analysis functions require a context. As I understand, they belong to certain package, but documentation doesn’t mention it.

It seems that the redfaced WordCount, WordCounts, and LetterCounts are shadowed by some other definitions in your working environment, cmp. the following sequence about Smith:

In[1]:= $ContextPath
Out[1]= {"PacletManager`", "System`", "Global`"}

In[2]:= {PhysicalUnits`Smith, BioDiversity`Smith}
Out[2]= {PhysicalUnits`Smith, BioDiversity`Smith}

In[3]:= $ContextPath = Join[{"PhysicalUnits`", "BioDiversity`"}, $ContextPath]
Out[3]= {"PhysicalUnits`", "BioDiversity`", "PacletManager`", "System`", "Global`"}

In[4]:= Context[Smith]
Out[4]= "PhysicalUnits`"

In[5]:= Smith = 3 (* not a good idea *); PhysicalUnits`Smith = 4; BioDiversity`Smith = 5;

In[6]:= Context[Smith]
Out[6]= "PhysicalUnits`"

In[8]:= Smith + Smith + BioDiversity`Smith (* 4 + 4 + 5 *)
Out[8]= 13

In[9]:= Global`Smith + Smith + BioDiversity`Smith (* 3 + 4 + 5 *)
During evaluation of In[9]:= Global`Smith::shdw: Symbol Smith appears in multiple contexts {Global`,PhysicalUnits`,BioDiversity`}; definitions in context Global` may shadow or be shadowed by other definitions. >>
Out[9]= 9 + Global`Smith

checkout whether some other packages are preloaded, which contain names nowadays given the above mentioned redfaced built-in functions.