There are two type of BIO, a source/sink BIO and a filter BIO.
-As its name implies a source/sink BIO is a source or sink of data,
+As its name implies a source/sink BIO is a source and/or sink of data,
examples include a socket BIO and a file BIO.
A filter BIO takes data from one BIO and passes it through to
BIOs can be joined together to form a chain (a single BIO is a chain
with one component). A chain normally consist of one source/sink
BIO and one or more filter BIOs. Data read from or written to the
-end BIO then traverses the chain to the end (normally a source/sink
+first BIO then traverses the chain to the end (normally a source/sink
BIO).
=head1 SEE ALSO
-TBA
+L<BIO_ctrl(3)|BIO_ctrl(3)>,
+L<BIO_f_base64(3)|BIO_f_base64(3)>, L<BIO_f_buffer(3)|BIO_f_buffer(3)>,
+L<BIO_f_cipher(3)|BIO_f_cipher(3)>, L<BIO_f_md(3)|BIO_f_md(3)>,
+L<BIO_f_null(3)|BIO_f_null(3)>, L<BIO_f_ssl(3)|BIO_f_ssl(3)>,
+L<BIO_find_type(3)|BIO_find_type(3)>, L<BIO_new(3)|BIO_new(3)>,
+L<BIO_new_bio_pair(3)|BIO_new_bio_pair(3)>,
+L<BIO_push(3)|BIO_push(3)>, L<BIO_read(3)|BIO_read(3)>,
+L<BIO_s_accept(3)|BIO_s_accept(3)>, L<BIO_s_bio(3)|BIO_s_bio(3)>,
+L<BIO_s_connect(3)|BIO_s_connect(3)>, L<BIO_s_fd(3)|BIO_s_fd(3)>,
+L<BIO_s_file(3)|BIO_s_file(3)>, L<BIO_s_mem(3)|BIO_s_mem(3)>,
+L<BIO_s_null(3)|BIO_s_null(3)>, L<BIO_s_socket(3)|BIO_s_socket(3)>,
+L<BIO_set_callback(3)|BIO_set_callback(3)>,
+L<BIO_should_retry(3)|BIO_should_retry(3)>