diff --git a/R/helpers.R b/R/helpers.R
index f57100a..05d855c 100644
--- a/R/helpers.R
+++ b/R/helpers.R
@@ -791,8 +791,18 @@
     for(i in seq_along(row)){
 
       if(names(row)[i] == "position"){
+        inVal <- 1
+        outVal <- 0
+
+        if(any(names(row) %in% "invert")){
+          if(row$invert){
+            inVal <- 0
+            outVal <- 1
+          }
+        }
+
         rows <- input %>%
-          mutate(it = if_else(row_number() %in% row[[i]], 1, 0)) %>%
+          mutate(it = if_else(row_number() %in% row[[i]], inVal, outVal)) %>%
           pull(it)
       } else if(names(row)[i] == "find"){
 
diff --git a/R/schema.R b/R/schema.R
index aad046c..f7954c3 100755
--- a/R/schema.R
+++ b/R/schema.R
@@ -162,7 +162,7 @@ setValidity(Class = "schema", function(object){
       errors <- c(errors, "'names(schema$format)' must be a permutation of set {header,del,dec,na,flags}")
     }
     if(!is.null(object@format$header)){
-      if(!is.integer(object@format$header)){
+      if(!is_integerish(object@format$header)){
         errors <- c(errors, "'schema$format$header' must must have a integer value.")
       }
     }
diff --git a/R/setFilter.R b/R/setFilter.R
index c5b730f..9f2a952 100644
--- a/R/setFilter.R
+++ b/R/setFilter.R
@@ -7,6 +7,8 @@
 #' @param rows [\code{integerish(.)}]\cr rows that are mentioned here are kept.
 #' @param columns [\code{integerish(.)}]\cr columns that are mentioned here are
 #'   kept.
+#' @param invert [\code{logical(1)}]\cr whether or not to invert the specified
+#'   columns or rows.
 #' @param operator [\code{function(1)}]\cr \code{\link[base]{Logic}} operators
 #'   by which the current filter should be combined with the directly preceeding
 #'   filter; hence this argument is not used in case no other filter was defined
@@ -27,10 +29,10 @@
 #'
 #' reorganise(schema = schema, input = input)
 #' @family functions to describe table arrangement
-#' @importFrom checkmate assertClass testIntegerish testClass
+#' @importFrom checkmate assertClass testIntegerish testClass assertLogical
 #' @export
 
-setFilter <- function(schema = NULL, rows = NULL, columns = NULL,
+setFilter <- function(schema = NULL, rows = NULL, columns = NULL, invert = FALSE,
                       operator = NULL){
 
   # assertions ----
@@ -43,6 +45,7 @@ setFilter <- function(schema = NULL, rows = NULL, columns = NULL,
   assert(colInt, colList)
   if(rowList) assertSubset(x = names(rows), choices = c("find"))
   if(colList) assertSubset(x = names(columns), choices = c("find"))
+  assertLogical(x = invert, any.missing = FALSE)
 
   # update schema ----
   if(is.null(schema)){
@@ -55,7 +58,7 @@ setFilter <- function(schema = NULL, rows = NULL, columns = NULL,
 
   if(!is.null(rows)){
     if(!is.list(rows)){
-      rows <- list(position = rows)
+      rows <- list(position = rows, invert = invert)
     }
     if(!is.null(schema@filter$row)){
       rows <- c(operator = operator, rows)
diff --git a/R/setFormat.R b/R/setFormat.R
index 3ef222a..8ae8322 100644
--- a/R/setFormat.R
+++ b/R/setFormat.R
@@ -33,12 +33,12 @@
 #' @importFrom dplyr bind_rows
 #' @export
 
-setFormat <- function(schema = NULL, header = 0L, decimal = NULL,
+setFormat <- function(schema = NULL, header = 0, decimal = NULL,
                       thousand = NULL, na_values = NULL, flags = NULL){
 
   # assertions ----
   assertClass(x = schema, classes = "schema", null.ok = TRUE)
-  assertIntegerish(x = header, len = 1, lower = 0L, any.missing = FALSE)
+  assertIntegerish(x = header, len = 1, lower = 0, any.missing = FALSE)
   assertCharacter(x = decimal, len = 1, any.missing = FALSE, null.ok = TRUE)
   assertCharacter(x = thousand, len = 1, any.missing = FALSE, null.ok = TRUE)
   assertCharacter(x = na_values, any.missing = FALSE, null.ok = TRUE)
diff --git a/man/setFilter.Rd b/man/setFilter.Rd
index 065e70a..c8fcc48 100644
--- a/man/setFilter.Rd
+++ b/man/setFilter.Rd
@@ -4,7 +4,13 @@
 \alias{setFilter}
 \title{Set filters}
 \usage{
-setFilter(schema = NULL, rows = NULL, columns = NULL, operator = NULL)
+setFilter(
+  schema = NULL,
+  rows = NULL,
+  columns = NULL,
+  invert = FALSE,
+  operator = NULL
+)
 }
 \arguments{
 \item{schema}{[\code{schema(1)}]\cr In case this information is added to an
@@ -16,6 +22,9 @@ information).}
 \item{columns}{[\code{integerish(.)}]\cr columns that are mentioned here are
 kept.}
 
+\item{invert}{[\code{logical(1)}]\cr whether or not to invert the specified
+columns or rows.}
+
 \item{operator}{[\code{function(1)}]\cr \code{\link[base]{Logic}} operators
 by which the current filter should be combined with the directly preceeding
 filter; hence this argument is not used in case no other filter was defined
diff --git a/man/setFormat.Rd b/man/setFormat.Rd
index f8ba549..68e52ab 100644
--- a/man/setFormat.Rd
+++ b/man/setFormat.Rd
@@ -6,7 +6,7 @@
 \usage{
 setFormat(
   schema = NULL,
-  header = 0L,
+  header = 0,
   decimal = NULL,
   thousand = NULL,
   na_values = NULL,