diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000000000000000000000000000000000000..3faa54d96dda3af8d4e29ab8b4c8101470f6ca41
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,66 @@
+### Questions and bug reports
+
+If you have questions about the usage of a function or would like to report a bug, please follow these steps:
+
+1. Use the search function in GitLab to see if a similar problem has already been reported and/or solved.
+
+2. Rather than including a long script, try to run your code in small blocks to narrow down where the problem is coming from as much as possible.
+
+3. Open an issue tagging the maintainers (@tkariyat), and include a descriptive title and a piece of code to reproduce your problem (if applicable).
+
+### How to contribute
+
+If you would like to add a bugfix, an enhancement or a new functions, follow these steps:
+
+1. Open an issue to ask for help or describe a feature to be integrated
+
+2. Agree with the maintainers (@tkariyat) on the requirements
+
+3. Create a new branch from master with a meaningful name
+
+4. Once the development is finished, open a merge request to merge the branch on master
+
+*Note: Remember to work with multidimensional arrays with named dimensions when possible and use multiApply (https://earth.bsc.es/gitlab/ces/multiApply)*
+
+### Adding a function
+
+To add a new function in this R package, follow these considerations:
+
+* Each function exposed to the users should be in its own separate file in the R folder
+* The name of the function should match the name of the file (e.g.: `Function()` included in file **Function.R**
+* The documentation should be in roxygen2 format as a header of the function
+* Once the function and the documentation are finished, run the command `devtools::document()` in your R terminal to automatically generate the **Function.Rd** file
+* When doing the development, please use an R version between R/4.1.2 and R/4.3.x 
+
+### Style guide
+
+* Use `<-` for variable assignment
+* Include spaces between operators (e.g. `+`, `-`, `&`), before `{`, and after `for`, `if`, `while`, `,` and `)`.
+* When possible, maximum line length should be 100 characters (soft limit of 80 characters).
+* Number of indentation spaces is 2, using tabs for indentation is forbidden.
+* Double quotes are recommended for strings. When writing quotes within quoted text, use double quotes outside and single quotes inside. E.g.: `“Parameter 'na.rm' is missing.”`
+* Self-explanatory names are preferred for variables. Try to be consistent with the variable naming style. Generally: avoid special characters (except underscores) and reserved words (ex: if, for, else, …)
+* Remember to include short comments to make the code easier to understand. Comments should be in their own line and they should start with `#` followed by a space. Comments that start with `##` and a space are for details not needed to understand the general procedure but useful to make note of more technical aspects of the code.
+
+#### Examples:
+
+```r
+# Proper spacing, indentation spaces and text quotes:
+NewFunction <- function(text = "default", uppercase = TRUE) {
+  # Check uppercase parameter
+  if (!is.logical(uppercase)) {
+    stop("Parameter 'uppercase' should be TRUE or FALSE.")
+  }
+  # Only transform text if needed
+  if (uppercase && is.character(text)) {
+    text <- toupper(text)
+  }
+  return(text)
+}
+
+# How to format line breaks to avoid long lines:
+my_strings <- list(one = "one",
+                   two = "two",
+                   three = "three",
+                   four = "four")
+```
diff --git a/R/PeriodStandardization.R b/R/PeriodStandardization.R
index b71270f14086d2db804f4a046b0766b6f1952edc..00ebc71e9d89a57abad615e4d512c286582da3b1 100644
--- a/R/PeriodStandardization.R
+++ b/R/PeriodStandardization.R
@@ -125,7 +125,10 @@ CST_PeriodStandardization <- function(data, data_cor = NULL, time_dim = 'syear',
 
   if (is.null(data_cor)) {
     data$data <- std
-    data$attrs$Variable$varName <- paste0(data$attrs$Variable$varName, ' standardized')
+    data_longname <- data$attrs$Variable$metadata[[data$attrs$Variable$varName]]$longname
+    if (!is.null(data_longname)) {
+      data$attrs$Variable$metadata[[data$attrs$Variable$varName]]$longname <- paste(data_longname, 'standardized')
+    }
     if (return_params) {
       return(list(spei = data, params = params))
     } else {
@@ -133,7 +136,10 @@ CST_PeriodStandardization <- function(data, data_cor = NULL, time_dim = 'syear',
     }
   } else {
     data_cor$data <- std
-    data_cor$attrs$Variable$varName <- paste0(data_cor$attrs$Variable$varName, ' standardized')
+    data_cor_longname <- data_cor$attrs$Variable$metadata[[data_cor$attrs$Variable$varName]]$longname
+    if (!is.null(data_cor_longname)) {
+      data_cor$attrs$Variable$metadata[[data_cor$attrs$Variable$varName]]$longname <- paste(data_cor_longname, 'standardized')
+    }
     data_cor$attrs$Datasets <- c(data_cor$attrs$Datasets, data$attrs$Datasets)
     data_cor$attrs$source_files <- c(data_cor$attrs$source_files, data$attrs$source_files)
     return(data_cor)
@@ -644,4 +650,4 @@ PeriodStandardization <- function(data, data_cor = NULL, dates = NULL,
   } else {
     return(NA)
   }
-}
\ No newline at end of file
+}
diff --git a/tests/testthat/test-PeriodStandardization.R b/tests/testthat/test-PeriodStandardization.R
index 1e816c005efe765d119cfc0645b787d5780b8390..4def61da1641df7e5fe61f82c4384f647e8e7252 100644
--- a/tests/testthat/test-PeriodStandardization.R
+++ b/tests/testthat/test-PeriodStandardization.R
@@ -38,7 +38,15 @@ dims3 <- c(syear = 6, time = 2, lat = 2, ensemble = 25)
 set.seed(1)
 dat3 <- array(abs(rnorm(600, 21.19, 25.64)), dim = dims)
 
-
+# dat4
+test <- NULL
+test$data <- array(rnorm(600, -204.1, 78.1), dim = dims)
+test$dims <- dims
+test$coords <- setNames(as.list(as.numeric(test$dims)), names(test$dims))
+test$attrs <- list(Variable = list(varName = 'prlr',
+                                   metadata = list(units = "m s-1", 
+                                                   longname = "Total precipitation")))
+class(test) <- 's2dv_cube'
 ##############################################
 
 test_that("1. Initial checks CST_PeriodStandardization", {
@@ -152,11 +160,18 @@ test_that("1. Initial checks PeriodStandardization", {
 
 test_that("2. Output checks", {
   # CST_PeriodStandardization
+  prlr <- CST_PeriodStandardization(data = test)
+  expect_equal(
+    names(prlr),
+    c("data", "dims", "coords", "attrs")
+  )
+  
   SPEI_s2dv_cube <- CST_PeriodStandardization(data = cube1)
   expect_equal(
     names(SPEI_s2dv_cube),
-    c('data', 'attrs')
+    c('data')
   )
+  
   # PeriodStandardization
   SPEI <- PeriodStandardization(data = dat1)
   expect_equal(