diff --git a/core/src/main/java/org/verapdf/pdfa/validation/validators/BaseValidator.java b/core/src/main/java/org/verapdf/pdfa/validation/validators/BaseValidator.java
index 7fcf07a21..6aa439fea 100644
--- a/core/src/main/java/org/verapdf/pdfa/validation/validators/BaseValidator.java
+++ b/core/src/main/java/org/verapdf/pdfa/validation/validators/BaseValidator.java
@@ -298,11 +298,7 @@ private boolean checkAllRules(Object checkObject, String checkContext) {
 	private boolean firstProcessObjectWithRule(Object checkObject, String checkContext, Rule rule) {
 		Boolean deferred = rule.getDeferred();
 		if (deferred != null && deferred.booleanValue()) {
-			List<ObjectWithContext> list = this.deferredRules.get(rule);
-			if (list == null) {
-				list = new ArrayList<>();
-				this.deferredRules.put(rule, list);
-			}
+			List<ObjectWithContext> list = this.deferredRules.computeIfAbsent(rule, k -> new ArrayList<>());
 			list.add(new ObjectWithContext(checkObject, checkContext));
 			return true;
 		}
diff --git a/core/src/main/java/org/verapdf/processor/reports/RuleSummary.java b/core/src/main/java/org/verapdf/processor/reports/RuleSummary.java
index b43a4c6a1..a49858016 100644
--- a/core/src/main/java/org/verapdf/processor/reports/RuleSummary.java
+++ b/core/src/main/java/org/verapdf/processor/reports/RuleSummary.java
@@ -45,7 +45,7 @@ public interface RuleSummary {
     public int getTestNumber();
     public String getStatus();
     public Status getRuleStatus();
-    public int getPassedChecks();
+    public Integer getPassedChecks();
     public int getFailedChecks();
     public Set<String> getTags();
     public String getDescription();
diff --git a/core/src/main/java/org/verapdf/processor/reports/RuleSummaryImpl.java b/core/src/main/java/org/verapdf/processor/reports/RuleSummaryImpl.java
index 2c62c73f6..9c7e15fe4 100644
--- a/core/src/main/java/org/verapdf/processor/reports/RuleSummaryImpl.java
+++ b/core/src/main/java/org/verapdf/processor/reports/RuleSummaryImpl.java
@@ -50,7 +50,7 @@ final class RuleSummaryImpl implements RuleSummary {
 	@XmlAttribute
 	private final String status;
 	@XmlAttribute
-	private final int passedChecks;
+	private final Integer passedChecks;
 	@XmlAttribute
 	private final int failedChecks;
 	@XmlAttribute
@@ -64,7 +64,7 @@ final class RuleSummaryImpl implements RuleSummary {
 	@XmlElement(name = "check")
 	private final List<Check> checks;
 
-	private RuleSummaryImpl(final RuleId ruleId, final Status status, final int passedChecks, final int failedChecks,
+	private RuleSummaryImpl(final RuleId ruleId, final Status status, final Integer passedChecks, final int failedChecks,
 			final String tags, final String description, final String object, final String test, final List<Check> checks) {
 		PDFAFlavour.Specification specification = ruleId.getSpecification();
 		this.specification = specification == null ? null : specification.getId();
@@ -135,7 +135,7 @@ public int getTestNumber() {
 	 * @return the passedChecks
 	 */
 	@Override
-	public int getPassedChecks() {
+	public Integer getPassedChecks() {
 		return this.passedChecks;
 	}
 
@@ -149,7 +149,7 @@ public int getFailedChecks() {
 
 	@Override
 	public Set<String> getTags() {
-		return tags != null ? new HashSet<>(Arrays.asList(tags.split(","))) : Collections.emptySet();
+		return tags != null ? new HashSet<>(Arrays.asList(tags.split(","))) : null;
 	}
 
 	/**
@@ -213,15 +213,13 @@ static final RuleSummary fromValues(final RuleId id, final String description, f
 		for (TestAssertion assertion : assertions) {
 			if (assertion.getStatus() == Status.PASSED) {
 				passedChecks++;
-				if (logPassedChecks) {
-					checks.add(CheckImpl.fromValue(assertion));
-				}
+				checks.add(CheckImpl.fromValue(assertion));
 			} else {
 				status = assertion.getStatus();
 				checks.add(CheckImpl.fromValue(assertion));
 			}
 		}
-		return new RuleSummaryImpl(id, status, passedChecks, failedChecks != null ? failedChecks : 0, tags, description, object, test, checks);
+		return new RuleSummaryImpl(id, status, logPassedChecks ? passedChecks : null, failedChecks != null ? failedChecks : 0, tags, description, object, test, checks);
 	}
 
 	static final RuleSummary uncheckedInstance(final RuleId id, final String description, final String object,
diff --git a/xmp-core/src/main/java/org/verapdf/xmp/impl/VeraPDFMeta.java b/xmp-core/src/main/java/org/verapdf/xmp/impl/VeraPDFMeta.java
index 104ee03b9..6dc137c45 100644
--- a/xmp-core/src/main/java/org/verapdf/xmp/impl/VeraPDFMeta.java
+++ b/xmp-core/src/main/java/org/verapdf/xmp/impl/VeraPDFMeta.java
@@ -15,6 +15,7 @@
 public class VeraPDFMeta {
 
     public static final String PDFAID_PREFIX = "pdfaid";
+    public static final String PDFUAID_PREFIX = "pdfuaid";
     public static final String CONFORMANCE = "conformance";
     public static final String PART = "part";
     public static final String REVISION_YEAR = "rev";