diff --git a/R/foreign.R b/R/foreign.R
index 0cf7c447f0..6c96a1a920 100644
--- a/R/foreign.R
+++ b/R/foreign.R
@@ -151,6 +151,9 @@ write.graph.fromraw <- function(buffer, file) {
 #' @keywords graphs
 #' @family foreign
 #' @export
+#' @cdocs igraph_read_graph_dimacs_flow igraph_read_graph_dl igraph_read_graph_edgelist
+#' @cdocs igraph_read_graph_gml igraph_read_graph_graphdb igraph_read_graph_graphml
+#' @cdocs igraph_read_graph_lgl igraph_read_graph_ncol igraph_read_graph_pajek
 read_graph <- function(file, format = c(
                          "edgelist", "pajek", "ncol", "lgl",
                          "graphml", "dimacs", "graphdb", "gml", "dl"
@@ -184,21 +187,34 @@ read_graph <- function(file, format = c(
 #' Writing the graph to a file in some format
 #'
 #' `write_graph()` is a general function for exporting graphs to foreign
-#' file formats, however not many formats are implemented right now.
+#' file formats. The recommended formats for data exchange are GraphML and GML.
 #'
 #' @param graph The graph to export.
 #' @param file A connection or a string giving the file name to write the graph
 #'   to.
 #' @param format Character string giving the file format. Right now
 #'   `pajek`, `graphml`, `dot`, `gml`, `edgelist`,
-#'   `lgl`, `ncol` and `dimacs` are implemented. As of igraph 0.4
+#'   `lgl`, `ncol`, `leda` and `dimacs` are implemented. As of igraph 0.4
 #'   this argument is case insensitive.
 #' @param \dots Other, format specific arguments, see below.
-#' @return A NULL, invisibly.
+#' @return A `NULL``, invisibly.
 #' @section Edge list format: The `edgelist` format is a simple text file,
-#' with one edge in a line, the two vertex ids separated by a space character.
+#' with one edge per line, the two zero-based numerical vertex IDs separated
+#' by a space character. Note that vertices are indexed starting with zero.
 #' The file is sorted by the first and the second column. This format has no
 #' additional arguments.
+#' @section NCOL format: This format is a plain text edge list in which vertices
+#' are referred to by name rather than numerical ID. Edge weights may be
+#' optionally written. Additional parameters:
+#' \describe{
+#' \item{names}{The name of a vertex attribute to take vertex names from or
+#' `NULL` to use zero-based numerical IDs.}
+#' \item{weights}{The name of an edge attribute to take edge weights from or
+#' `NULL` to omit edge weights.}
+#' }
+#' @section Pajek format: The `pajek` format is provided for interoperability
+#' with the Pajek software only. Since the format does not have a formal
+#' specification, it is not recommended for general data exchange or archival.
 #' @author Gabor Csardi \email{csardi.gabor@@gmail.com}
 #' @seealso [read_graph()]
 #' @references Adai AT, Date SV, Wieland S, Marcotte EM. LGL: creating a map of
@@ -207,6 +223,9 @@ read_graph <- function(file, format = c(
 #' @family foreign
 #' @export
 #' @keywords graphs
+#' @cdocs igraph_write_graph_dimacs_flow igraph_write_graph_dot igraph_write_graph_edgelist
+#' @cdocs igraph_write_graph_gml igraph_write_graph_graphml igraph_write_graph_leda 
+#' @cdocs igraph_write_graph_lgl igraph_write_graph_ncol igraph_write_graph_pajek
 #' @examples
 #'
 #' g <- make_ring(10)
diff --git a/man/read_graph.Rd b/man/read_graph.Rd
index 6cb6ec0b9a..6c553b3a7f 100644
--- a/man/read_graph.Rd
+++ b/man/read_graph.Rd
@@ -75,3 +75,5 @@ Gabor Csardi \email{csardi.gabor@gmail.com}
 }
 \concept{foreign}
 \keyword{graphs}
+\section{Related documentation in the C library}{\href{https://igraph.org/c/html/latest/igraph-Foreign.html#igraph_read_graph_dimacs_flow}{\code{igraph_read_graph_dimacs_flow()}}, \href{https://igraph.org/c/html/latest/igraph-Foreign.html#igraph_read_graph_dl}{\code{igraph_read_graph_dl()}}, \href{https://igraph.org/c/html/latest/igraph-Foreign.html#igraph_read_graph_edgelist}{\code{igraph_read_graph_edgelist()}}, \href{https://igraph.org/c/html/latest/igraph-Foreign.html#igraph_read_graph_gml}{\code{igraph_read_graph_gml()}}, \href{https://igraph.org/c/html/latest/igraph-Foreign.html#igraph_read_graph_graphdb}{\code{igraph_read_graph_graphdb()}}, \href{https://igraph.org/c/html/latest/igraph-Foreign.html#igraph_read_graph_graphml}{\code{igraph_read_graph_graphml()}}, \href{https://igraph.org/c/html/latest/igraph-Foreign.html#igraph_read_graph_lgl}{\code{igraph_read_graph_lgl()}}, \href{https://igraph.org/c/html/latest/igraph-Foreign.html#igraph_read_graph_ncol}{\code{igraph_read_graph_ncol()}}, \href{https://igraph.org/c/html/latest/igraph-Foreign.html#igraph_read_graph_pajek}{\code{igraph_read_graph_pajek()}}.}
+
diff --git a/man/write.graph.Rd b/man/write.graph.Rd
index 75798fb66c..c7376de875 100644
--- a/man/write.graph.Rd
+++ b/man/write.graph.Rd
@@ -20,7 +20,7 @@ to.}
 
 \item{format}{Character string giving the file format. Right now
 \code{pajek}, \code{graphml}, \code{dot}, \code{gml}, \code{edgelist},
-\code{lgl}, \code{ncol} and \code{dimacs} are implemented. As of igraph 0.4
+\code{lgl}, \code{ncol}, \code{leda} and \code{dimacs} are implemented. As of igraph 0.4
 this argument is case insensitive.}
 
 \item{...}{Other, format specific arguments, see below.}
diff --git a/man/write_graph.Rd b/man/write_graph.Rd
index 891d8b06c1..e3e2571bc8 100644
--- a/man/write_graph.Rd
+++ b/man/write_graph.Rd
@@ -20,25 +20,44 @@ to.}
 
 \item{format}{Character string giving the file format. Right now
 \code{pajek}, \code{graphml}, \code{dot}, \code{gml}, \code{edgelist},
-\code{lgl}, \code{ncol} and \code{dimacs} are implemented. As of igraph 0.4
+\code{lgl}, \code{ncol}, \code{leda} and \code{dimacs} are implemented. As of igraph 0.4
 this argument is case insensitive.}
 
 \item{\dots}{Other, format specific arguments, see below.}
 }
 \value{
-A NULL, invisibly.
+A `NULL``, invisibly.
 }
 \description{
 \code{write_graph()} is a general function for exporting graphs to foreign
-file formats, however not many formats are implemented right now.
+file formats. The recommended formats for data exchange are GraphML and GML.
 }
 \section{Edge list format}{
  The \code{edgelist} format is a simple text file,
-with one edge in a line, the two vertex ids separated by a space character.
+with one edge per line, the two zero-based numerical vertex IDs separated
+by a space character. Note that vertices are indexed starting with zero.
 The file is sorted by the first and the second column. This format has no
 additional arguments.
 }
 
+\section{NCOL format}{
+ This format is a plain text edge list in which vertices
+are referred to by name rather than numerical ID. Edge weights may be
+optionally written. Additional parameters:
+\describe{
+\item{names}{The name of a vertex attribute to take vertex names from or
+\code{NULL} to use zero-based numerical IDs.}
+\item{weights}{The name of an edge attribute to take edge weights from or
+\code{NULL} to omit edge weights.}
+}
+}
+
+\section{Pajek format}{
+ The \code{pajek} format is provided for interoperability
+with the Pajek software only. Since the format does not have a formal
+specification, it is not recommended for general data exchange or archival.
+}
+
 \examples{
 
 g <- make_ring(10)
@@ -66,3 +85,5 @@ Gabor Csardi \email{csardi.gabor@gmail.com}
 }
 \concept{foreign}
 \keyword{graphs}
+\section{Related documentation in the C library}{\href{https://igraph.org/c/html/latest/igraph-Foreign.html#igraph_write_graph_dimacs_flow}{\code{igraph_write_graph_dimacs_flow()}}, \href{https://igraph.org/c/html/latest/igraph-Foreign.html#igraph_write_graph_dot}{\code{igraph_write_graph_dot()}}, \href{https://igraph.org/c/html/latest/igraph-Foreign.html#igraph_write_graph_edgelist}{\code{igraph_write_graph_edgelist()}}, \href{https://igraph.org/c/html/latest/igraph-Foreign.html#igraph_write_graph_gml}{\code{igraph_write_graph_gml()}}, \href{https://igraph.org/c/html/latest/igraph-Foreign.html#igraph_write_graph_graphml}{\code{igraph_write_graph_graphml()}}, \href{https://igraph.org/c/html/latest/igraph-Foreign.html#igraph_write_graph_leda}{\code{igraph_write_graph_leda()}}, \href{https://igraph.org/c/html/latest/igraph-Foreign.html#igraph_write_graph_lgl}{\code{igraph_write_graph_lgl()}}, \href{https://igraph.org/c/html/latest/igraph-Foreign.html#igraph_write_graph_ncol}{\code{igraph_write_graph_ncol()}}, \href{https://igraph.org/c/html/latest/igraph-Foreign.html#igraph_write_graph_pajek}{\code{igraph_write_graph_pajek()}}.}
+