let help = "The format is a string with special patterns:
@{id} : id
@{authors} : authors (coma separated list)
@{authors-and} : authors (comas and a 'and' for the last one)
@{authors-bibtex} : authors (BibTeX friendly format)
@{authors-acm} : authors (like ACM Ref, with initials)
@{authors-etal} : authors
(Depending on the number of authors:
1: Lastname
2: Lastname1 and Lastname2
more: Lastname1 et al.)
@{title} : title
@{title-punct} : the title with a dot '.'
if not already ending with '?', '.', or '!'
@{how} : how
@{year} : year
@{note} : note
@{url} : url
@{pdfurl} : pdfurl
@{comment} : comment tagged \"main\" (or non-tagged)
@{comment-<tag>} : comment tagged \"tag\"
@{bibtex} : The (maybe generated) BibTeX entry
(if there's no `bibtex' field, the entry is generated,
like for the '-bibtex' option)
@{abstract} : abstract
@{doi} : doi
@{citation} : citation
@{tags} : tags (coma separated list)
@{keywords} : keywords (coma separated list)
@{@} : the '@' character
@{n} : the new-line character
@{if <expr>} AAA @{else} BBB @{endif} :
Evaluates <expr> for the entry,
if true, displays AAA, if not, BBB.
(<expr> uses the same syntax as the '-select' option,
see 'sebib -help-select')
"