Internal links — also known as hashtag links, intra-page links, bookmark links, or (officially) as links containing fragment identifiers — indicate a subordinate resource or section of a primary resource. In most cases, this means a discrete location on a web page. Were crawlers to follow these they would visit individual pages many more times that is necessary (or, in the case of most Wikipedia pages, dozens or hundreds of times).
Increasingly sites are using the
#-sign, will be spidered.