diff --git a/.Rbuildignore b/.Rbuildignore
index 232504f..56967a0 100644
--- a/.Rbuildignore
+++ b/.Rbuildignore
@@ -22,3 +22,7 @@
 ^\.jules(/.*)?$
 ^\.trivyignore\.yaml$
 ^trivy\.yaml$
+^\.semgrepignore$
+^test_dummy\.R$
+^test_validation\.R$
+^\.markdownlint-cli2\.jsonc$
diff --git a/.jules/sentinel.md b/.jules/sentinel.md
index a8207a4..47f1611 100644
--- a/.jules/sentinel.md
+++ b/.jules/sentinel.md
@@ -2,3 +2,8 @@
 **Vulnerability:** Unvalidated inputs passed to `if()` statements can cause process crashes (`condition has length > 1`) or unexpected coercion vulnerabilities.
 **Learning:** In R, optional boolean parameters that default to `NULL` should be validated using explicit runtime type validation (e.g., `if (!is.null(flag) && (!is.logical(flag) || length(flag) != 1 || is.na(flag)))`).
 **Prevention:** Always implement explicit runtime type validation for optional boolean parameters.
+
+## 2024-07-23 - Strict Numeric Input Validation for `readline()`
+**Vulnerability:** In R scripts, validating interactive `readline()` numeric inputs against unbounded digit classes (e.g., `^[0-9]+$`) rather than strict exact expected values (e.g., `^[12]$`) can cause integer overflow coercion vulnerabilities. Excessively large numeric strings will pass the regex check but evaluate to `NA` when coerced with `as.integer()`, causing downstream crashes or unexpected state.
+**Learning:** Bounded inputs must be strictly validated for the specific range expected rather than broadly accepting any number of digits, as unbounded strings bypass size limitations.
+**Prevention:** Always implement strict matching (e.g., `^[12]$`) against exact expected values for menu inputs rather than unbounded digit classes.
diff --git a/.markdownlint-cli2.jsonc b/.markdownlint-cli2.jsonc
new file mode 100644
index 0000000..2ef6cd9
--- /dev/null
+++ b/.markdownlint-cli2.jsonc
@@ -0,0 +1,8 @@
+{
+  "config": {
+    "MD013": false,
+    "MD022": false,
+    "MD041": false
+  },
+  "ignores": ["packrat/**"]
+}
diff --git a/R/aFIPC.R b/R/aFIPC.R
index 6254651..918e19b 100644
--- a/R/aFIPC.R
+++ b/R/aFIPC.R
@@ -141,7 +141,7 @@ autoFIPC <-
       }
       for (attempt in seq_len(3)) {
         n <- readline(prompt = "Is it correct? (1: Yes 2: No) : ")
-        if (grepl("^[0-9]+$", n)) {
+        if (grepl("^[12]$", n)) {
           return(as.integer(n))
         }
       }
@@ -171,7 +171,7 @@ autoFIPC <-
               readline(
                 prompt = "Do you want to use default BILOG-MG priors for oldform Data? (1: Yes 2: No) : "
               )
-            if (grepl("^[0-9]+$", n)) {
+            if (grepl("^[12]$", n)) {
               return(as.integer(n))
             }
           }
@@ -390,7 +390,7 @@ autoFIPC <-
               readline(
                 prompt = "Do you want to use default BILOG-MG priors for newform Data? (1: Yes 2: No) : "
               )
-            if (grepl("^[0-9]+$", n)) {
+            if (grepl("^[12]$", n)) {
               return(as.integer(n))
             }
           }